Use `spack commands --format=bash` to generate shell completion (#14393)

This PR adds a `--format=bash` option to `spack commands` to
auto-generate the Bash programmable tab completion script. It can be
extended to work for other shells.

Progress:

- [x] Fix bug in superclass initialization in `ArgparseWriter`
- [x] Refactor `ArgparseWriter` (see below)
- [x] Ensure that output of old `--format` options remains the same
- [x] Add `ArgparseCompletionWriter` and `BashCompletionWriter`
- [x] Add `--aliases` option to add command aliases
- [x] Standardize positional argument names
- [x] Tests for `spack commands --format=bash` coverage
- [x] Tests to make sure `spack-completion.bash` stays up-to-date
- [x] Tests for `spack-completion.bash` coverage
- [x] Speed up `spack-completion.bash` by caching subroutine calls

This PR also necessitates a significant refactoring of
`ArgparseWriter`. Previously, `ArgparseWriter` was mostly a single
`_write` method which handled everything from extracting the information
we care about from the parser to formatting the output. Now, `_write`
only handles recursion, while the information extraction is split into a
separate `parse` method, and the formatting is handled by `format`. This
allows subclasses to completely redefine how the format will appear
without overriding all of `_write`.

Co-Authored-by: Todd Gamblin <tgamblin@llnl.gov>

7 files changed, 1403 insertions, 709 deletions

diff --git a/share/spack/bash/spack-completion.in b/share/spack/bash/spack-completion.in
new file mode 100755
index 0000000000..2ab39a57a3
--- /dev/null
+++ b/share/spack/bash/spack-completion.in
@@ -0,0 +1,309 @@
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+# NOTE: spack-completion.bash is auto-generated by:
+#
+#   $ spack commands --aliases --format=bash
+#       --header=bash/spack-completion.in --update=spack-completion.bash
+#
+# Please do not manually modify this file.
+
+
+# The following global variables are set by Bash programmable completion:
+#
+#     COMP_CWORD:      An index into ${COMP_WORDS} of the word containing the
+#                      current cursor position
+#     COMP_KEY:        The key (or final key of a key sequence) used to invoke
+#                      the current completion function
+#     COMP_LINE:       The current command line
+#     COMP_POINT:      The index of the current cursor position relative to the
+#                      beginning of the current command
+#     COMP_TYPE:       Set to an integer value corresponding to the type of
+#                      completion attempted that caused a completion function
+#                      to be called
+#     COMP_WORDBREAKS: The set of characters that the readline library treats
+#                      as word separators when performing word completion
+#     COMP_WORDS:      An array variable consisting of the individual words in
+#                      the current command line
+#
+# The following global variable is used by Bash programmable completion:
+#
+#     COMPREPLY:       An array variable from which bash reads the possible
+#                      completions generated by a shell function invoked by the
+#                      programmable completion facility
+#
+# See `man bash` for more details.
+
+# Bash programmable completion for Spack
+_bash_completion_spack() {
+    # In all following examples, let the cursor be denoted by brackets, i.e. []
+
+    # For our purposes, flags should not affect tab completion. For instance,
+    # `spack install []` and `spack -d install --jobs 8 []` should both give the same
+    # possible completions. Therefore, we need to ignore any flags in COMP_WORDS.
+    local COMP_WORDS_NO_FLAGS=()
+    local index=0
+    while [[ "$index" -lt "$COMP_CWORD" ]]
+    do
+        if [[ "${COMP_WORDS[$index]}" == [a-z]* ]]
+        then
+            COMP_WORDS_NO_FLAGS+=("${COMP_WORDS[$index]}")
+        fi
+        let index++
+    done
+
+    # Options will be listed by a subfunction named after non-flag arguments.
+    # For example, `spack -d install []` will call _spack_install
+    # and `spack compiler add []` will call _spack_compiler_add
+    local subfunction=$(IFS='_'; echo "_${COMP_WORDS_NO_FLAGS[*]}")
+
+    # Translate dashes to underscores, as dashes are not permitted in
+    # compatibility mode. See https://github.com/spack/spack/pull/4079
+    subfunction=${subfunction//-/_}
+
+    # However, the word containing the current cursor position needs to be
+    # added regardless of whether or not it is a flag. This allows us to
+    # complete something like `spack install --keep-st[]`
+    COMP_WORDS_NO_FLAGS+=("${COMP_WORDS[$COMP_CWORD]}")
+
+    # Since we have removed all words after COMP_CWORD, we can safely assume
+    # that COMP_CWORD_NO_FLAGS is simply the index of the last element
+    local COMP_CWORD_NO_FLAGS=$((${#COMP_WORDS_NO_FLAGS[@]} - 1))
+
+    # There is no guarantee that the cursor is at the end of the command line
+    # when tab completion is envoked. For example, in the following situation:
+    #     `spack -d [] install`
+    # if the user presses the TAB key, a list of valid flags should be listed.
+    # Note that we cannot simply ignore everything after the cursor. In the
+    # previous scenario, the user should expect to see a list of flags, but
+    # not of other subcommands. Obviously, `spack -d list install` would be
+    # invalid syntax. To accomplish this, we use the variable list_options
+    # which is true if the current word starts with '-' or if the cursor is
+    # not at the end of the line.
+    local list_options=false
+    if [[ "${COMP_WORDS[$COMP_CWORD]}" == -* || "$COMP_POINT" -ne "${#COMP_LINE}" ]]
+    then
+        list_options=true
+    fi
+
+    # In general, when envoking tab completion, the user is not expecting to
+    # see optional flags mixed in with subcommands or package names. Tab
+    # completion is used by those who are either lazy or just bad at spelling.
+    # If someone doesn't remember what flag to use, seeing single letter flags
+    # in their results won't help them, and they should instead consult the
+    # documentation. However, if the user explicitly declares that they are
+    # looking for a flag, we can certainly help them out.
+    #     `spack install -[]`
+    # and
+    #     `spack install --[]`
+    # should list all flags and long flags, respectively. Furthermore, if a
+    # subcommand has no non-flag completions, such as `spack arch []`, it
+    # should list flag completions.
+
+    local cur=${COMP_WORDS_NO_FLAGS[$COMP_CWORD_NO_FLAGS]}
+
+    # If the cursor is in the middle of the line, like:
+    #     `spack -d [] install`
+    # COMP_WORDS will not contain the empty character, so we have to add it.
+    if [[ "${COMP_LINE:$COMP_POINT:1}" == " " ]]
+    then
+        cur=""
+    fi
+
+    # Uncomment this line to enable logging
+    #_test_vars >> temp
+
+    # Make sure function exists before calling it
+    if [[ "$(type -t $subfunction)" == "function" ]]
+    then
+        $subfunction
+        COMPREPLY=($(compgen -W "$SPACK_COMPREPLY" -- "$cur"))
+    fi
+}
+
+# Helper functions for subcommands
+# Results of each query are cached via environment variables
+
+_subcommands() {
+    if [[ -z "${SPACK_SUBCOMMANDS:-}" ]]
+    then
+        SPACK_SUBCOMMANDS="$(spack commands)"
+    fi
+    SPACK_COMPREPLY="$SPACK_SUBCOMMANDS"
+}
+
+_all_packages() {
+    if [[ -z "${SPACK_ALL_PACKAGES:-}" ]]
+    then
+        SPACK_ALL_PACKAGES="$(spack list)"
+    fi
+    SPACK_COMPREPLY="$SPACK_ALL_PACKAGES"
+}
+
+_all_resource_hashes() {
+    if [[ -z "${SPACK_ALL_RESOURCES_HASHES:-}" ]]
+    then
+        SPACK_ALL_RESOURCE_HASHES="$(spack resource list --only-hashes)"
+    fi
+    SPACK_COMPREPLY="$SPACK_ALL_RESOURCE_HASHES"
+}
+
+_installed_packages() {
+    if [[ -z "${SPACK_INSTALLED_PACKAGES:-}" ]]
+    then
+        SPACK_INSTALLED_PACKAGES="$(spack --color=never find --no-groups)"
+    fi
+    SPACK_COMPREPLY="$SPACK_INSTALLED_PACKAGES"
+}
+
+_installed_compilers() {
+    if [[ -z "${SPACK_INSTALLED_COMPILERS:-}" ]]
+    then
+        SPACK_INSTALLED_COMPILERS="$(spack compilers | egrep -v "^(-|=)")"
+    fi
+    SPACK_COMPREPLY="$SPACK_INSTALLED_COMPILERS"
+}
+
+_providers() {
+    if [[ -z "${SPACK_PROVIDERS:-}" ]]
+    then
+        SPACK_PROVIDERS="$(spack providers)"
+    fi
+    SPACK_COMPREPLY="$SPACK_PROVIDERS"
+}
+
+_mirrors() {
+    if [[ -z "${SPACK_MIRRORS:-}" ]]
+    then
+        SPACK_MIRRORS="$(spack mirror list | awk '{print $1}')"
+    fi
+    SPACK_COMPREPLY="$SPACK_MIRRORS"
+}
+
+_repos() {
+    if [[ -z "${SPACK_REPOS:-}" ]]
+    then
+        SPACK_REPOS="$(spack repo list | awk '{print $1}')"
+    fi
+    SPACK_COMPREPLY="$SPACK_REPOS"
+}
+
+_tests() {
+    if [[ -z "${SPACK_TESTS:-}" ]]
+    then
+        SPACK_TESTS="$(spack test -l)"
+    fi
+    SPACK_COMPREPLY="$SPACK_TESTS"
+}
+
+_environments() {
+    if [[ -z "${SPACK_ENVIRONMENTS:-}" ]]
+    then
+        SPACK_ENVIRONMENTS="$(spack env list)"
+    fi
+    SPACK_COMPREPLY="$SPACK_ENVIRONMENTS"
+}
+
+_keys() {
+    if [[ -z "${SPACK_KEYS:-}" ]]
+    then
+        SPACK_KEYS="$(spack gpg list)"
+    fi
+    SPACK_COMPREPLY="$SPACK_KEYS"
+}
+
+_config_sections() {
+    if [[ -z "${SPACK_CONFIG_SECTIONS:-}" ]]
+    then
+        SPACK_CONFIG_SECTIONS="compilers mirrors repos packages modules config upstreams"
+    fi
+    SPACK_COMPREPLY="$SPACK_CONFIG_SECTIONS"
+}
+
+_extensions() {
+    if [[ -z "${SPACK_EXTENSIONS:-}" ]]
+    then
+        SPACK_EXTENSIONS="aspell go-bootstrap go icedtea jdk kim-api lua matlab mofem-cephas octave openjdk perl python r ruby rust tcl yorick"
+    fi
+    SPACK_COMPREPLY="$SPACK_EXTENSIONS"
+}
+
+# Testing functions
+
+# Function for unit testing tab completion
+# Syntax: _spack_completions spack install py-
+_spack_completions() {
+    local COMP_CWORD COMP_KEY COMP_LINE COMP_POINT COMP_TYPE COMP_WORDS COMPREPLY
+
+    # Set each variable the way bash would
+    COMP_LINE="$*"
+    COMP_POINT=${#COMP_LINE}
+    COMP_WORDS=("$@")
+    if [[ ${COMP_LINE: -1} == ' ' ]]
+    then
+        COMP_WORDS+=('')
+    fi
+    COMP_CWORD=$((${#COMP_WORDS[@]} - 1))
+    COMP_KEY=9    # ASCII 09: Horizontal Tab
+    COMP_TYPE=64  # ASCII 64: '@', to list completions if the word is not unmodified
+
+    # Run Spack's tab completion function
+    _bash_completion_spack
+
+    # Return the result
+    echo "${COMPREPLY[@]:-}"
+}
+
+# Log the environment variables used
+# Syntax: _test_vars >> temp
+_test_vars() {
+    echo "-----------------------------------------------------"
+    echo "Variables set by bash:"
+    echo
+    echo "COMP_LINE:                '$COMP_LINE'"
+    echo "# COMP_LINE:              '${#COMP_LINE}'"
+    echo "COMP_WORDS:               $(_pretty_print COMP_WORDS[@])"
+    echo "# COMP_WORDS:             '${#COMP_WORDS[@]}'"
+    echo "COMP_CWORD:               '$COMP_CWORD'"
+    echo "COMP_KEY:                 '$COMP_KEY'"
+    echo "COMP_POINT:               '$COMP_POINT'"
+    echo "COMP_TYPE:                '$COMP_TYPE'"
+    echo "COMP_WORDBREAKS:          '$COMP_WORDBREAKS'"
+    echo
+    echo "Intermediate variables:"
+    echo
+    echo "COMP_WORDS_NO_FLAGS:      $(_pretty_print COMP_WORDS_NO_FLAGS[@])"
+    echo "# COMP_WORDS_NO_FLAGS:    '${#COMP_WORDS_NO_FLAGS[@]}'"
+    echo "COMP_CWORD_NO_FLAGS:      '$COMP_CWORD_NO_FLAGS'"
+    echo
+    echo "Subfunction:              '$subfunction'"
+    if $list_options
+    then
+        echo "List options:             'True'"
+    else
+        echo "List options:             'False'"
+    fi
+    echo "Current word:             '$cur'"
+}
+
+# Pretty-prints one or more arrays
+# Syntax: _pretty_print array1[@] ...
+_pretty_print() {
+    for arg in $@
+    do
+        local array=("${!arg}")
+        printf "$arg: ["
+        printf   "'%s'" "${array[0]}"
+        printf ", '%s'" "${array[@]:1}"
+        echo "]"
+    done
+}
+
+complete -o bashdefault -o default -F _bash_completion_spack spack
+
+# Spack commands
+#
+# Everything below here is auto-generated.
diff --git a/share/spack/qa/completion-test.sh b/share/spack/qa/completion-test.sh
new file mode 100755
index 0000000000..5b326b4a6d
--- /dev/null
+++ b/share/spack/qa/completion-test.sh
@@ -0,0 +1,89 @@
+#!/bin/sh
+#
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+#
+# This script tests that Spack's tab completion scripts work.
+#
+# The tests are portable to bash, zsh, and bourne shell, and can be run
+# in any of these shells.
+#
+
+export QA_DIR=$(dirname "$0")
+export SHARE_DIR=$(cd "$QA_DIR/.." && pwd)
+export SPACK_ROOT=$(cd "$QA_DIR/../../.." && pwd)
+
+. "$QA_DIR/test-framework.sh"
+
+# Fail on undefined variables
+set -u
+
+# Source setup-env.sh before tests
+. "$SHARE_DIR/setup-env.sh"
+. "$SHARE_DIR/spack-completion.$_sp_shell"
+
+title "Testing spack-completion.$_sp_shell with $_sp_shell"
+
+# Spack command is now available
+succeeds which spack
+
+title 'Testing all subcommands'
+while IFS= read -r line
+do
+    # Test that completion with no args works
+    succeeds _spack_completions ${line[*]} ''
+
+    # Test that completion with flags works
+    contains '-h --help' _spack_completions ${line[*]} -
+done <<- EOF
+    $(spack commands --aliases --format=subcommands)
+EOF
+
+title 'Testing for correct output'
+contains 'compiler' _spack_completions spack ''
+contains 'install' _spack_completions spack inst
+contains 'find' _spack_completions spack help ''
+contains 'hdf5' _spack_completions spack list ''
+contains 'py-numpy' _spack_completions spack list py-
+contains 'mpi' _spack_completions spack providers ''
+contains 'builtin' _spack_completions spack repo remove ''
+contains 'packages' _spack_completions spack config edit ''
+contains 'python' _spack_completions spack extensions ''
+contains 'hdf5' _spack_completions spack -d install --jobs 8 ''
+contains 'hdf5' _spack_completions spack install -v ''
+
+# XFAIL: Fails for Python 2.6 because pkg_resources not found?
+#contains 'compilers.py' _spack_completions spack test ''
+
+title 'Testing debugging functions'
+
+# This is a particularly tricky case that involves the following situation:
+#     `spack -d [] install `
+# Here, [] represents the cursor, which is in the middle of the line.
+# We should tab-complete optional flags for `spack`, not optional flags for
+# `spack install` or package names.
+COMP_LINE='spack -d  install '
+COMP_POINT=9
+COMP_WORDS=(spack -d install)
+COMP_CWORD=2
+COMP_KEY=9
+COMP_TYPE=64
+
+_bash_completion_spack
+contains "--all-help" echo "${COMPREPLY[@]}"
+
+contains "['spack', '-d', 'install', '']" _pretty_print COMP_WORDS[@]
+
+# Set the rest of the intermediate variables manually
+COMP_WORDS_NO_FLAGS=(spack install)
+COMP_CWORD_NO_FLAGS=1
+subfunction=_spack
+cur=
+
+list_options=true
+contains "'True'" _test_vars
+list_options=false
+contains "'False'" _test_vars
diff --git a/share/spack/qa/run-unit-tests b/share/spack/qa/run-unit-tests
index 8ba6eed350..52748dacdf 100755
--- a/share/spack/qa/run-unit-tests
+++ b/share/spack/qa/run-unit-tests
@@ -23,7 +23,7 @@
 ORIGINAL_PATH="$PATH"
 
 . "$(dirname $0)/setup.sh"
-check_dependencies ${coverage} git hg svn
+check_dependencies $coverage git hg svn
 
 # Move to root directory of Spack
 # Allows script to be run from anywhere
@@ -46,7 +46,7 @@ extra_args=""
 if [[ -n "$@" ]]; then
     extra_args="-k $@"
 fi
-${coverage_run} bin/spack test -x --verbose "$extra_args"
+$coverage_run bin/spack test -x --verbose "$extra_args"
 
 #-----------------------------------------------------------
 # Run tests for setup-env.sh
@@ -57,15 +57,18 @@ export PATH="$ORIGINAL_PATH"
 unset spack
 
 # start in the spack root directory
-cd $SPACK_ROOT
+cd "$SPACK_ROOT"
 
 # Run bash tests with coverage enabled, but pipe output to /dev/null
 # because it seems that kcov seems to undo the script's redirection
 if [ "$BASH_COVERAGE" = true ]; then
-    ${QA_DIR}/bashcov ${QA_DIR}/setup-env-test.sh &> /dev/null
+    "$QA_DIR/bashcov" "$QA_DIR/setup-env-test.sh" &> /dev/null
+    "$QA_DIR/bashcov" "$QA_DIR/completion-test.sh" &> /dev/null
 fi
 
 # run the test scripts for their output (these will print nicely)
-bash ${QA_DIR}/setup-env-test.sh
-zsh  ${QA_DIR}/setup-env-test.sh
-dash ${QA_DIR}/setup-env-test.sh
+bash "$QA_DIR/setup-env-test.sh"
+zsh  "$QA_DIR/setup-env-test.sh"
+dash "$QA_DIR/setup-env-test.sh"
+
+bash "$QA_DIR/completion-test.sh"
diff --git a/share/spack/qa/setup-env-test.sh b/share/spack/qa/setup-env-test.sh
index 7613637984..66284d1a96 100755
--- a/share/spack/qa/setup-env-test.sh
+++ b/share/spack/qa/setup-env-test.sh
@@ -12,159 +12,11 @@
 # in any of these shells.
 #
 
-# ------------------------------------------------------------------------
-# Functions for color output.
-# ------------------------------------------------------------------------
-
-# Colors for output
-red='\033[1;31m'
-cyan='\033[1;36m'
-green='\033[1;32m'
-reset='\033[0m'
-
-echo_red() {
-    printf "${red}$*${reset}\n"
-}
-
-echo_green() {
-    printf "${green}$*${reset}\n"
-}
-
-echo_msg() {
-    printf "${cyan}$*${reset}\n"
-}
-
-# ------------------------------------------------------------------------
-# Generic functions for testing shell code.
-# ------------------------------------------------------------------------
-
-# counts of test successes and failures.
-success=0
-errors=0
-
-# Print out a header for a group of tests.
-title() {
-    echo
-    echo_msg "$@"
-    echo_msg "---------------------------------"
-}
-
-# echo FAIL in red text; increment failures
-fail() {
-    echo_red FAIL
-    errors=$((errors+1))
-}
-
-#
-# Echo SUCCESS in green; increment successes
-#
-pass() {
-    echo_green SUCCESS
-    success=$((success+1))
-}
-
-#
-# Run a command and suppress output unless it fails.
-# On failure, echo the exit code and output.
-#
-succeeds() {
-    printf "'%s' succeeds ... " "$*"
-    output=$($* 2>&1)
-    err="$?"
-
-    if [ "$err" != 0 ]; then
-        fail
-        echo_red "Command failed with error $err."
-        if [ -n "$output" ]; then
-            echo_msg "Output:"
-            echo "$output"
-        else
-            echo_msg "No output."
-        fi
-    else
-        pass
-    fi
-}
-
-#
-# Run a command and suppress output unless it succeeds.
-# If the command succeeds, echo the output.
-#
-fails() {
-    printf "'%s' fails ... " "$*"
-    output=$("$@" 2>&1)
-    err="$?"
-
-    if [ "$err" = 0 ]; then
-        fail
-        echo_red "Command failed with error $err."
-        if [ -n "$output" ]; then
-            echo_msg "Output:"
-            echo "$output"
-        else
-            echo_msg "No output."
-        fi
-    else
-        pass
-    fi
-}
-
-#
-# Ensure that a string is in the output of a command.
-# Suppresses output on success.
-# On failure, echo the exit code and output.
-#
-contains() {
-    string="$1"
-    shift
-
-    printf "'%s' output contains '$string' ... " "$*"
-    output=$("$@" 2>&1)
-    err="$?"
-
-    if [ "${output#*$string}" = "${output}" ]; then
-        fail
-        echo_red "Command exited with error $err."
-        echo_red "'$string' was not in output."
-        if [ -n "$output" ]; then
-            echo_msg "Output:"
-            echo "$output"
-        else
-            echo_msg "No output."
-        fi
-    else
-        pass
-    fi
-}
-
-#
-# Ensure that a variable is set.
-#
-is_set() {
-    printf "'%s' is set ... " "$1"
-    if eval "[ -z \${${1:-}+x} ]"; then
-        fail
-        echo_msg "$1 was not set!"
-    else
-        pass
-    fi
-}
-
-#
-# Ensure that a variable is not set.
-# Fails and prints the value of the variable if it is set.
-#
-is_not_set() {
-    printf "'%s' is not set ... " "$1"
-    if eval "[ ! -z \${${1:-}+x} ]"; then
-        fail
-        echo_msg "$1 was set:"
-        echo "    $1"
-    else
-        pass
-    fi
-}
+export QA_DIR=$(dirname "$0")
+export SHARE_DIR=$(cd "$QA_DIR/.." && pwd)
+export SPACK_ROOT=$(cd "$QA_DIR/../../.." && pwd)
 
+. "$QA_DIR/test-framework.sh"
 
 # -----------------------------------------------------------------------
 # Instead of invoking the module commands, we print the
@@ -184,28 +36,28 @@ module() {
 # Make sure no environment is active
 unset SPACK_ENV
 
-# fail on undefined variables
+# Fail on undefined variables
 set -u
 
 # Source setup-env.sh before tests
-.  share/spack/setup-env.sh
+. "$SHARE_DIR/setup-env.sh"
 
-# bash should expand aliases even when non-interactive
+# Bash should expand aliases even when non-interactive
 if [ -n "${BASH:-}" ]; then
     shopt -s expand_aliases
 fi
 
 title "Testing setup-env.sh with $_sp_shell"
 
-# spack command is now avaialble
+# Spack command is now available
 succeeds which spack
 
-# mock cd command (intentionally define only AFTER setup-env.sh)
+# Mock cd command (intentionally define only AFTER setup-env.sh)
 cd() {
     echo cd "$@"
 }
 
-# create a fake mock package install and store its location for later
+# Create a fake mock package install and store its location for later
 title "Setup"
 echo "Creating a mock package installation"
 spack -m install --fake a
@@ -215,19 +67,13 @@ a_module=$(spack -m module tcl find a)
 b_install=$(spack location -i b)
 b_module=$(spack -m module tcl find b)
 
-# create a test environment for tesitng environment commands
+# Create a test environment for testing environment commands
 echo "Creating a mock environment"
 spack env create spack_test_env
 test_env_location=$(spack location -e spack_test_env)
 
-# ensure that we uninstall b on exit
+# Ensure that we uninstall b on exit
 cleanup() {
-    if [ "$?" != 0 ]; then
-        trapped_error=true
-    else
-        trapped_error=false
-    fi
-
     echo "Removing test environment before exiting."
     spack env deactivate 2>&1 > /dev/null
     spack env rm -y spack_test_env
@@ -235,24 +81,7 @@ cleanup() {
     title "Cleanup"
     echo "Removing test packages before exiting."
     spack -m uninstall -yf b a
-
-    echo
-    echo "$success tests succeeded."
-    echo "$errors tests failed."
-
-    if [ "$trapped_error" = true ]; then
-        echo "Exited due to an error."
-    fi
-
-    if [ "$errors" = 0 ] && [ "$trapped_error" = false ]; then
-        pass
-        exit 0
-    else
-        fail
-        exit 1
-    fi
 }
-trap cleanup EXIT
 
 # -----------------------------------------------------------------------
 # Test all spack commands with special env support
diff --git a/share/spack/qa/test-framework.sh b/share/spack/qa/test-framework.sh
new file mode 100755
index 0000000000..14b58bbecf
--- /dev/null
+++ b/share/spack/qa/test-framework.sh
@@ -0,0 +1,195 @@
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+#
+# A testing framework for any POSIX-compatible shell.
+#
+
+# ------------------------------------------------------------------------
+# Functions for color output.
+# ------------------------------------------------------------------------
+
+# Colors for output
+red='\033[1;31m'
+cyan='\033[1;36m'
+green='\033[1;32m'
+reset='\033[0m'
+
+echo_red() {
+    printf "${red}$*${reset}\n"
+}
+
+echo_green() {
+    printf "${green}$*${reset}\n"
+}
+
+echo_msg() {
+    printf "${cyan}$*${reset}\n"
+}
+
+# ------------------------------------------------------------------------
+# Generic functions for testing shell code.
+# ------------------------------------------------------------------------
+
+# counts of test successes and failures.
+success=0
+errors=0
+
+# Print out a header for a group of tests.
+title() {
+    echo
+    echo_msg "$@"
+    echo_msg "---------------------------------"
+}
+
+# echo FAIL in red text; increment failures
+fail() {
+    echo_red FAIL
+    errors=$((errors+1))
+}
+
+#
+# Echo SUCCESS in green; increment successes
+#
+pass() {
+    echo_green SUCCESS
+    success=$((success+1))
+}
+
+#
+# Run a command and suppress output unless it fails.
+# On failure, echo the exit code and output.
+#
+succeeds() {
+    printf "'%s' succeeds ... " "$*"
+    output=$("$@" 2>&1)
+    err="$?"
+
+    if [ "$err" != 0 ]; then
+        fail
+        echo_red "Command failed with error $err."
+        if [ -n "$output" ]; then
+            echo_msg "Output:"
+            echo "$output"
+        else
+            echo_msg "No output."
+        fi
+    else
+        pass
+    fi
+}
+
+#
+# Run a command and suppress output unless it succeeds.
+# If the command succeeds, echo the output.
+#
+fails() {
+    printf "'%s' fails ... " "$*"
+    output=$("$@" 2>&1)
+    err="$?"
+
+    if [ "$err" = 0 ]; then
+        fail
+        echo_red "Command failed with error $err."
+        if [ -n "$output" ]; then
+            echo_msg "Output:"
+            echo "$output"
+        else
+            echo_msg "No output."
+        fi
+    else
+        pass
+    fi
+}
+
+#
+# Ensure that a string is in the output of a command.
+# Suppresses output on success.
+# On failure, echo the exit code and output.
+#
+contains() {
+    string="$1"
+    shift
+
+    printf "'%s' output contains '$string' ... " "$*"
+    output=$("$@" 2>&1)
+    err="$?"
+
+    if [ "${output#*$string}" = "${output}" ]; then
+        fail
+        echo_red "Command exited with error $err."
+        echo_red "'$string' was not in output."
+        if [ -n "$output" ]; then
+            echo_msg "Output:"
+            echo "$output"
+        else
+            echo_msg "No output."
+        fi
+    else
+        pass
+    fi
+}
+
+#
+# Ensure that a variable is set.
+#
+is_set() {
+    printf "'%s' is set ... " "$1"
+    if eval "[ -z \${${1:-}+x} ]"; then
+        fail
+        echo_msg "$1 was not set!"
+    else
+        pass
+    fi
+}
+
+#
+# Ensure that a variable is not set.
+# Fails and prints the value of the variable if it is set.
+#
+is_not_set() {
+    printf "'%s' is not set ... " "$1"
+    if eval "[ ! -z \${${1:-}+x} ]"; then
+        fail
+        echo_msg "$1 was set:"
+        echo "    $1"
+    else
+        pass
+    fi
+}
+
+#
+# Report the number of tests that succeeded and failed on exit.
+#
+teardown() {
+    if [ "$?" != 0 ]; then
+        trapped_error=true
+    else
+        trapped_error=false
+    fi
+
+    if type cleanup &> /dev/null
+    then
+        cleanup
+    fi
+
+    echo
+    echo "$success tests succeeded."
+    echo "$errors tests failed."
+
+    if [ "$trapped_error" = true ]; then
+        echo "Exited due to an error."
+    fi
+
+    if [ "$errors" = 0 ] && [ "$trapped_error" = false ]; then
+        pass
+        exit 0
+    else
+        fail
+        exit 1
+    fi
+}
+
+trap teardown EXIT
diff --git a/share/spack/qa/update-completion-scripts.sh b/share/spack/qa/update-completion-scripts.sh
new file mode 100755
index 0000000000..8fcd321457
--- /dev/null
+++ b/share/spack/qa/update-completion-scripts.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+#
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+# Updates Spack's shell tab completion scripts
+
+# Switch to parent directory
+QA_DIR="$(dirname "${BASH_SOURCE[0]}")"
+cd "$QA_DIR/.."
+
+# Update each shell
+for shell in bash # zsh fish
+do
+    header=$shell/spack-completion.in
+    script=spack-completion.$shell
+
+    rm -f $script
+    spack commands --aliases --format=$shell --header=$header --update=$script
+    chmod +x $script
+done
diff --git a/share/spack/spack-completion.bash b/share/spack/spack-completion.bash
index a8dcbff5c0..0284e81113 100755
--- a/share/spack/spack-completion.bash
+++ b/share/spack/spack-completion.bash
@@ -4,16 +4,41 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 
-# The following global variables are used/set by Bash programmable completion
-#     COMP_CWORD: An index into ${COMP_WORDS} of the word containing the
-#                 current cursor position
-#     COMP_LINE:  The current command line
-#     COMP_WORDS: an array containing individual command arguments typed so far
-#     COMPREPLY:  an array containing possible completions as a result of your
-#                 function
+# NOTE: spack-completion.bash is auto-generated by:
+#
+#   $ spack commands --aliases --format=bash
+#       --header=bash/spack-completion.in --update=spack-completion.bash
+#
+# Please do not manually modify this file.
+
+
+# The following global variables are set by Bash programmable completion:
+#
+#     COMP_CWORD:      An index into ${COMP_WORDS} of the word containing the
+#                      current cursor position
+#     COMP_KEY:        The key (or final key of a key sequence) used to invoke
+#                      the current completion function
+#     COMP_LINE:       The current command line
+#     COMP_POINT:      The index of the current cursor position relative to the
+#                      beginning of the current command
+#     COMP_TYPE:       Set to an integer value corresponding to the type of
+#                      completion attempted that caused a completion function
+#                      to be called
+#     COMP_WORDBREAKS: The set of characters that the readline library treats
+#                      as word separators when performing word completion
+#     COMP_WORDS:      An array variable consisting of the individual words in
+#                      the current command line
+#
+# The following global variable is used by Bash programmable completion:
+#
+#     COMPREPLY:       An array variable from which bash reads the possible
+#                      completions generated by a shell function invoked by the
+#                      programmable completion facility
+#
+# See `man bash` for more details.
 
 # Bash programmable completion for Spack
-_bash_completion_spack () {
+_bash_completion_spack() {
     # In all following examples, let the cursor be denoted by brackets, i.e. []
 
     # For our purposes, flags should not affect tab completion. For instance,
@@ -46,7 +71,7 @@ _bash_completion_spack () {
 
     # Since we have removed all words after COMP_CWORD, we can safely assume
     # that COMP_CWORD_NO_FLAGS is simply the index of the last element
-    local COMP_CWORD_NO_FLAGS=$(( ${#COMP_WORDS_NO_FLAGS[@]} - 1 ))
+    local COMP_CWORD_NO_FLAGS=$((${#COMP_WORDS_NO_FLAGS[@]} - 1))
 
     # There is no guarantee that the cursor is at the end of the command line
     # when tab completion is envoked. For example, in the following situation:
@@ -59,8 +84,7 @@ _bash_completion_spack () {
     # which is true if the current word starts with '-' or if the cursor is
     # not at the end of the line.
     local list_options=false
-    if [[ "${COMP_WORDS[$COMP_CWORD]}" == -* || \
-          "$COMP_CWORD" -ne "${#COMP_WORDS[@]}-1" ]]
+    if [[ "${COMP_WORDS[$COMP_CWORD]}" == -* || "$COMP_POINT" -ne "${#COMP_LINE}" ]]
     then
         list_options=true
     fi
@@ -80,1266 +104,1488 @@ _bash_completion_spack () {
     # should list flag completions.
 
     local cur=${COMP_WORDS_NO_FLAGS[$COMP_CWORD_NO_FLAGS]}
-    local prev=${COMP_WORDS_NO_FLAGS[$COMP_CWORD_NO_FLAGS-1]}
 
-    #_test_vars
+    # If the cursor is in the middle of the line, like:
+    #     `spack -d [] install`
+    # COMP_WORDS will not contain the empty character, so we have to add it.
+    if [[ "${COMP_LINE:$COMP_POINT:1}" == " " ]]
+    then
+        cur=""
+    fi
+
+    # Uncomment this line to enable logging
+    #_test_vars >> temp
 
     # Make sure function exists before calling it
     if [[ "$(type -t $subfunction)" == "function" ]]
     then
-        COMPREPLY=($($subfunction))
+        $subfunction
+        COMPREPLY=($(compgen -W "$SPACK_COMPREPLY" -- "$cur"))
+    fi
+}
+
+# Helper functions for subcommands
+# Results of each query are cached via environment variables
+
+_subcommands() {
+    if [[ -z "${SPACK_SUBCOMMANDS:-}" ]]
+    then
+        SPACK_SUBCOMMANDS="$(spack commands)"
+    fi
+    SPACK_COMPREPLY="$SPACK_SUBCOMMANDS"
+}
+
+_all_packages() {
+    if [[ -z "${SPACK_ALL_PACKAGES:-}" ]]
+    then
+        SPACK_ALL_PACKAGES="$(spack list)"
+    fi
+    SPACK_COMPREPLY="$SPACK_ALL_PACKAGES"
+}
+
+_all_resource_hashes() {
+    if [[ -z "${SPACK_ALL_RESOURCES_HASHES:-}" ]]
+    then
+        SPACK_ALL_RESOURCE_HASHES="$(spack resource list --only-hashes)"
+    fi
+    SPACK_COMPREPLY="$SPACK_ALL_RESOURCE_HASHES"
+}
+
+_installed_packages() {
+    if [[ -z "${SPACK_INSTALLED_PACKAGES:-}" ]]
+    then
+        SPACK_INSTALLED_PACKAGES="$(spack --color=never find --no-groups)"
+    fi
+    SPACK_COMPREPLY="$SPACK_INSTALLED_PACKAGES"
+}
+
+_installed_compilers() {
+    if [[ -z "${SPACK_INSTALLED_COMPILERS:-}" ]]
+    then
+        SPACK_INSTALLED_COMPILERS="$(spack compilers | egrep -v "^(-|=)")"
+    fi
+    SPACK_COMPREPLY="$SPACK_INSTALLED_COMPILERS"
+}
+
+_providers() {
+    if [[ -z "${SPACK_PROVIDERS:-}" ]]
+    then
+        SPACK_PROVIDERS="$(spack providers)"
+    fi
+    SPACK_COMPREPLY="$SPACK_PROVIDERS"
+}
+
+_mirrors() {
+    if [[ -z "${SPACK_MIRRORS:-}" ]]
+    then
+        SPACK_MIRRORS="$(spack mirror list | awk '{print $1}')"
+    fi
+    SPACK_COMPREPLY="$SPACK_MIRRORS"
+}
+
+_repos() {
+    if [[ -z "${SPACK_REPOS:-}" ]]
+    then
+        SPACK_REPOS="$(spack repo list | awk '{print $1}')"
+    fi
+    SPACK_COMPREPLY="$SPACK_REPOS"
+}
+
+_tests() {
+    if [[ -z "${SPACK_TESTS:-}" ]]
+    then
+        SPACK_TESTS="$(spack test -l)"
+    fi
+    SPACK_COMPREPLY="$SPACK_TESTS"
+}
+
+_environments() {
+    if [[ -z "${SPACK_ENVIRONMENTS:-}" ]]
+    then
+        SPACK_ENVIRONMENTS="$(spack env list)"
+    fi
+    SPACK_COMPREPLY="$SPACK_ENVIRONMENTS"
+}
+
+_keys() {
+    if [[ -z "${SPACK_KEYS:-}" ]]
+    then
+        SPACK_KEYS="$(spack gpg list)"
+    fi
+    SPACK_COMPREPLY="$SPACK_KEYS"
+}
+
+_config_sections() {
+    if [[ -z "${SPACK_CONFIG_SECTIONS:-}" ]]
+    then
+        SPACK_CONFIG_SECTIONS="compilers mirrors repos packages modules config upstreams"
+    fi
+    SPACK_COMPREPLY="$SPACK_CONFIG_SECTIONS"
+}
+
+_extensions() {
+    if [[ -z "${SPACK_EXTENSIONS:-}" ]]
+    then
+        SPACK_EXTENSIONS="aspell go-bootstrap go icedtea jdk kim-api lua matlab mofem-cephas octave openjdk perl python r ruby rust tcl yorick"
+    fi
+    SPACK_COMPREPLY="$SPACK_EXTENSIONS"
+}
+
+# Testing functions
+
+# Function for unit testing tab completion
+# Syntax: _spack_completions spack install py-
+_spack_completions() {
+    local COMP_CWORD COMP_KEY COMP_LINE COMP_POINT COMP_TYPE COMP_WORDS COMPREPLY
+
+    # Set each variable the way bash would
+    COMP_LINE="$*"
+    COMP_POINT=${#COMP_LINE}
+    COMP_WORDS=("$@")
+    if [[ ${COMP_LINE: -1} == ' ' ]]
+    then
+        COMP_WORDS+=('')
+    fi
+    COMP_CWORD=$((${#COMP_WORDS[@]} - 1))
+    COMP_KEY=9    # ASCII 09: Horizontal Tab
+    COMP_TYPE=64  # ASCII 64: '@', to list completions if the word is not unmodified
+
+    # Run Spack's tab completion function
+    _bash_completion_spack
+
+    # Return the result
+    echo "${COMPREPLY[@]:-}"
+}
+
+# Log the environment variables used
+# Syntax: _test_vars >> temp
+_test_vars() {
+    echo "-----------------------------------------------------"
+    echo "Variables set by bash:"
+    echo
+    echo "COMP_LINE:                '$COMP_LINE'"
+    echo "# COMP_LINE:              '${#COMP_LINE}'"
+    echo "COMP_WORDS:               $(_pretty_print COMP_WORDS[@])"
+    echo "# COMP_WORDS:             '${#COMP_WORDS[@]}'"
+    echo "COMP_CWORD:               '$COMP_CWORD'"
+    echo "COMP_KEY:                 '$COMP_KEY'"
+    echo "COMP_POINT:               '$COMP_POINT'"
+    echo "COMP_TYPE:                '$COMP_TYPE'"
+    echo "COMP_WORDBREAKS:          '$COMP_WORDBREAKS'"
+    echo
+    echo "Intermediate variables:"
+    echo
+    echo "COMP_WORDS_NO_FLAGS:      $(_pretty_print COMP_WORDS_NO_FLAGS[@])"
+    echo "# COMP_WORDS_NO_FLAGS:    '${#COMP_WORDS_NO_FLAGS[@]}'"
+    echo "COMP_CWORD_NO_FLAGS:      '$COMP_CWORD_NO_FLAGS'"
+    echo
+    echo "Subfunction:              '$subfunction'"
+    if $list_options
+    then
+        echo "List options:             'True'"
+    else
+        echo "List options:             'False'"
     fi
+    echo "Current word:             '$cur'"
 }
 
+# Pretty-prints one or more arrays
+# Syntax: _pretty_print array1[@] ...
+_pretty_print() {
+    for arg in $@
+    do
+        local array=("${!arg}")
+        printf "$arg: ["
+        printf   "'%s'" "${array[0]}"
+        printf ", '%s'" "${array[@]:1}"
+        echo "]"
+    done
+}
+
+complete -o bashdefault -o default -F _bash_completion_spack spack
+
 # Spack commands
+#
+# Everything below here is auto-generated.
 
-_spack () {
+_spack() {
     if $list_options
     then
-        compgen -W "-h --help -H --all-help --color -C --config-scope -d --debug --timestamp --pdb -e --env -D --env-dir -E --no-env --use-env-repo -k --insecure -l --enable-locks -L --disable-locks -m --mock -p --profile --sorted-profile --lines -v --verbose --stacktrace -V --version --print-shell-vars" -- "$cur"
+        SPACK_COMPREPLY="-h --help -H --all-help --color -C --config-scope -d --debug --timestamp --pdb -e --env -D --env-dir -E --no-env --use-env-repo -k --insecure -l --enable-locks -L --disable-locks -m --mock -p --profile --sorted-profile --lines -v --verbose --stacktrace -V --version --print-shell-vars"
     else
-        compgen -W "$(_subcommands)" -- "$cur"
+        SPACK_COMPREPLY="activate add arch blame bootstrap build build-env buildcache cd checksum ci clean clone commands compiler compilers concretize config configure create deactivate debug dependencies dependents deprecate dev-build diy docs edit env extensions fetch find flake8 gc gpg graph help info install license list load location log-parse maintainers mirror module patch pkg providers pydoc python reindex remove rm repo resource restage setup spec stage test uninstall unload upload-s3 url verify versions view"
     fi
 }
 
-_spack_activate () {
+_spack_activate() {
     if $list_options
     then
-        compgen -W "-h --help -f --force -v --view" -- "$cur"
+        SPACK_COMPREPLY="-h --help -f --force -v --view"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_add () {
+_spack_add() {
     if $list_options
     then
-        compgen -W "-h --help -l --list-name" -- "$cur"
+        SPACK_COMPREPLY="-h --help -l --list-name"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_arch () {
-    compgen -W "-h --help --known-targets -p --platform -o --operating-system -t --target -f --frontend -b --backend" -- "$cur"
+_spack_arch() {
+    SPACK_COMPREPLY="-h --help --known-targets -p --platform -o --operating-system -t --target -f --frontend -b --backend"
 }
 
-_spack_blame () {
+_spack_blame() {
     if $list_options
     then
-        compgen -W "-h --help -t --time -p --percent -g --git" -- "$cur"
+        SPACK_COMPREPLY="-h --help -t --time -p --percent -g --git"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_bootstrap () {
-    compgen -W "-h --help -j --jobs --keep-prefix --keep-stage -n --no-checksum -v --verbose --use-cache --no-cache --cache-only --clean --dirty" -- "$cur"
+_spack_bootstrap() {
+    SPACK_COMPREPLY="-h --help -j --jobs --keep-prefix --keep-stage -n --no-checksum -v --verbose --use-cache --no-cache --cache-only --clean --dirty"
 }
 
-_spack_build () {
+_spack_build() {
     if $list_options
     then
-        compgen -W "-h --help -v --verbose" -- "$cur"
+        SPACK_COMPREPLY="-h --help -v --verbose"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_build_env () {
+_spack_build_env() {
     if $list_options
     then
-        compgen -W "-h --help --clean --dirty --dump --pickle" -- "$cur"
+        SPACK_COMPREPLY="-h --help --clean --dirty --dump --pickle"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_buildcache () {
+_spack_buildcache() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "create install list keys preview check download get-buildcache-name save-yaml copy update-index" -- "$cur"
+        SPACK_COMPREPLY="create install list keys preview check download get-buildcache-name save-yaml copy update-index"
     fi
 }
 
-_spack_buildcache_create () {
+_spack_buildcache_create() {
     if $list_options
     then
-        compgen -W "-h --help -r --rel -f --force -u --unsigned -a --allow-root -k --key -d --directory --no-rebuild-index -y --spec-yaml --no-deps" -- "$cur"
+        SPACK_COMPREPLY="-h --help -r --rel -f --force -u --unsigned -a --allow-root -k --key -d --directory --no-rebuild-index -y --spec-yaml --no-deps"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_buildcache_install () {
+_spack_buildcache_install() {
     if $list_options
     then
-        compgen -W "-h --help -f --force -m --multiple -a --allow-root -u --unsigned" -- "$cur"
+        SPACK_COMPREPLY="-h --help -f --force -m --multiple -a --allow-root -u --unsigned"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_buildcache_list () {
+_spack_buildcache_list() {
     if $list_options
     then
-        compgen -W "-h --help -l --long -L --very-long -v --variants -f --force" -- "$cur"
+        SPACK_COMPREPLY="-h --help -l --long -L --very-long -v --variants -f --force"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_buildcache_keys () {
-    compgen -W "-h --help -i --install -t --trust -f --force" -- "$cur"
+_spack_buildcache_keys() {
+    SPACK_COMPREPLY="-h --help -i --install -t --trust -f --force"
 }
 
-_spack_buildcache_preview () {
+_spack_buildcache_preview() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_buildcache_check () {
-    compgen -W "-h --help -m --mirror-url -o --output-file --scope -s --spec -y --spec-yaml --rebuild-on-error" -- "$cur"
+_spack_buildcache_check() {
+    SPACK_COMPREPLY="-h --help -m --mirror-url -o --output-file --scope -s --spec -y --spec-yaml --rebuild-on-error"
 }
 
-_spack_buildcache_download () {
-    compgen -W "-h --help -s --spec -y --spec-yaml -p --path -c --require-cdashid" -- "$cur"
+_spack_buildcache_download() {
+    SPACK_COMPREPLY="-h --help -s --spec -y --spec-yaml -p --path -c --require-cdashid"
 }
 
-_spack_buildcache_get_buildcache_name () {
-    compgen -W "-h --help -s --spec -y --spec-yaml" -- "$cur"
+_spack_buildcache_get_buildcache_name() {
+    SPACK_COMPREPLY="-h --help -s --spec -y --spec-yaml"
 }
 
-_spack_buildcache_save_yaml () {
-    compgen -W "-h --help --root-spec --root-spec-yaml -s --specs -y --yaml-dir" -- "$cur"
+_spack_buildcache_save_yaml() {
+    SPACK_COMPREPLY="-h --help --root-spec --root-spec-yaml -s --specs -y --yaml-dir"
 }
 
-_spack_buildcache_copy () {
-    compgen -W "-h --help --base-dir --spec-yaml --destination-url" -- "$cur"
+_spack_buildcache_copy() {
+    SPACK_COMPREPLY="-h --help --base-dir --spec-yaml --destination-url"
 }
 
-_spack_buildcache_update_index () {
-    compgen -W "-h --help -d --mirror-url" -- "$cur"
+_spack_buildcache_update_index() {
+    SPACK_COMPREPLY="-h --help -d --mirror-url"
 }
 
-_spack_cd () {
+_spack_cd() {
     if $list_options
     then
-        compgen -W "-h --help -m --module-dir -r --spack-root -i --install-dir -p --package-dir -P --packages -s --stage-dir -S --stages -b --build-dir -e --env" -- "$cur"
+        SPACK_COMPREPLY="-h --help -m --module-dir -r --spack-root -i --install-dir -p --package-dir -P --packages -s --stage-dir -S --stages -b --build-dir -e --env"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_checksum () {
+_spack_checksum() {
     if $list_options
     then
-        compgen -W "-h --help --keep-stage" -- "$cur"
+        SPACK_COMPREPLY="-h --help --keep-stage"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_clean () {
+_spack_ci() {
     if $list_options
     then
-        compgen -W "-h --help -s --stage -d --downloads -m --misc-cache -p --python-cache -a --all" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        SPACK_COMPREPLY="start generate pushyaml rebuild"
     fi
 }
 
-_spack_clone () {
+_spack_ci_start() {
+    SPACK_COMPREPLY="-h --help --output-file --copy-to --spack-repo --spack-ref --downstream-repo --branch-name --commit-sha"
+}
+
+_spack_ci_generate() {
+    SPACK_COMPREPLY="-h --help --output-file --copy-to --spack-repo --spack-ref"
+}
+
+_spack_ci_pushyaml() {
+    SPACK_COMPREPLY="-h --help --downstream-repo --branch-name --commit-sha"
+}
+
+_spack_ci_rebuild() {
+    SPACK_COMPREPLY="-h --help"
+}
+
+_spack_clean() {
     if $list_options
     then
-        compgen -W "-h --help -r --remote" -- "$cur"
+        SPACK_COMPREPLY="-h --help -s --stage -d --downloads -m --misc-cache -p --python-cache -a --all"
+    else
+        _all_packages
     fi
 }
 
-_spack_commands () {
+_spack_clone() {
     if $list_options
     then
-        compgen -W "-h --help --format --header --update" -- "$cur"
+        SPACK_COMPREPLY="-h --help -r --remote"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_compiler () {
+_spack_commands() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help -a --aliases --format --header --update"
     else
-        compgen -W "find add remove rm list info" -- "$cur"
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_compiler_find () {
+_spack_compiler() {
     if $list_options
     then
-        compgen -W "-h --help --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        SPACK_COMPREPLY="find add remove rm list info"
     fi
 }
 
-_spack_compiler_add () {
-    # Alias to `spack compiler find`
-    _spack_compiler_find
+_spack_compiler_find() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help --scope"
+    else
+        SPACK_COMPREPLY=""
+    fi
 }
 
-_spack_compiler_remove () {
+_spack_compiler_add() {
     if $list_options
     then
-        compgen -W "-h --help -a --all --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --scope"
     else
-        compgen -W "$(_installed_compilers)" -- "$cur"
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_compiler_rm () {
-    # Alias to `spack compiler remove`
-    _spack_compiler_remove
+_spack_compiler_remove() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help -a --all --scope"
+    else
+        _installed_compilers
+    fi
+}
+
+_spack_compiler_rm() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help -a --all --scope"
+    else
+        _installed_compilers
+    fi
 }
 
-_spack_compiler_list () {
-    compgen -W "-h --help --scope" -- "$cur"
+_spack_compiler_list() {
+    SPACK_COMPREPLY="-h --help --scope"
 }
 
-_spack_compiler_info () {
+_spack_compiler_info() {
     if $list_options
     then
-        compgen -W "-h --help --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --scope"
     else
-        compgen -W "$(_installed_compilers)" -- "$cur"
+        _installed_compilers
     fi
 }
 
-_spack_compilers () {
-    # Alias to `spack compiler list`
-    _spack_compiler_list
+_spack_compilers() {
+    SPACK_COMPREPLY="-h --help --scope"
 }
 
-_spack_concretize () {
-    compgen -W "-h --help -f --force" -- "$cur"
+_spack_concretize() {
+    SPACK_COMPREPLY="-h --help -f --force"
 }
 
-_spack_config () {
+_spack_config() {
     if $list_options
     then
-        compgen -W "-h --help --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --scope"
     else
-        compgen -W "get blame edit" -- "$cur"
+        SPACK_COMPREPLY="get blame edit"
     fi
 }
 
-_spack_config_get () {
+_spack_config_get() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "compilers mirrors repos packages modules config upstreams" -- "$cur"
+        _config_sections
     fi
 }
 
-_spack_config_blame () {
+_spack_config_blame() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "compilers mirrors repos packages modules config upstreams" -- "$cur"
+        _config_sections
     fi
 }
 
-_spack_config_edit () {
+_spack_config_edit() {
     if $list_options
     then
-        compgen -W "-h --help --print-file" -- "$cur"
+        SPACK_COMPREPLY="-h --help --print-file"
     else
-        compgen -W "compilers mirrors repos packages modules config upstreams" -- "$cur"
+        _config_sections
     fi
 }
 
-_spack_configure () {
+_spack_configure() {
     if $list_options
     then
-        compgen -W "-h --help -v --verbose" -- "$cur"
+        SPACK_COMPREPLY="-h --help -v --verbose"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_create () {
+_spack_create() {
     if $list_options
     then
-        compgen -W "-h --help --keep-stage -n --name -t --template -r --repo -N --namespace -f --force --skip-editor" -- "$cur"
+        SPACK_COMPREPLY="-h --help --keep-stage -n --name -t --template -r --repo -N --namespace -f --force --skip-editor"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_deactivate () {
+_spack_deactivate() {
     if $list_options
     then
-        compgen -W "-h --help -f --force -v --view -a --all" -- "$cur"
+        SPACK_COMPREPLY="-h --help -f --force -v --view -a --all"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_debug () {
+_spack_debug() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "create-db-tarball" -- "$cur"
+        SPACK_COMPREPLY="create-db-tarball"
     fi
 }
 
-_spack_debug_create_db_tarball () {
-    compgen -W "-h --help" -- "$cur"
+_spack_debug_create_db_tarball() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_dependencies () {
+_spack_dependencies() {
     if $list_options
     then
-        compgen -W "-h --help -i --installed -t --transitive --deptype -V --no-expand-virtuals" -- "$cur"
+        SPACK_COMPREPLY="-h --help -i --installed -t --transitive --deptype -V --no-expand-virtuals"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_dependents () {
+_spack_dependents() {
     if $list_options
     then
-        compgen -W "-h --help -i --installed -t --transitive" -- "$cur"
+        SPACK_COMPREPLY="-h --help -i --installed -t --transitive"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_deprecate () {
+_spack_deprecate() {
     if $list_options
     then
-        compgen -W "-h --help -y --yes-to-all -d --dependencies -D --no-dependencies -i --install-deprecator -I --no-install-deprecator -l --link-type" -- "$cur"
+        SPACK_COMPREPLY="-h --help -y --yes-to-all -d --dependencies -D --no-dependencies -i --install-deprecator -I --no-install-deprecator -l --link-type"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_dev_build () {
+_spack_dev_build() {
     if $list_options
     then
-        compgen -W "-h --help -j --jobs -d --source-path -i --ignore-dependencies -n --no-checksum --keep-prefix --skip-patch -q --quiet -u --until --clean --dirty" -- "$cur"
+        SPACK_COMPREPLY="-h --help -j --jobs -d --source-path -i --ignore-dependencies -n --no-checksum --keep-prefix --skip-patch -q --quiet -u --until --clean --dirty"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_diy () {
+_spack_diy() {
     if $list_options
     then
-        compgen -W "-h --help -j --jobs -d --source-path -i --ignore-dependencies -n --no-checksum --keep-prefix --skip-patch -q --quiet -u --until --clean --dirty" -- "$cur"
+        SPACK_COMPREPLY="-h --help -j --jobs -d --source-path -i --ignore-dependencies -n --no-checksum --keep-prefix --skip-patch -q --quiet -u --until --clean --dirty"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_docs () {
-    compgen -W "-h --help" -- "$cur"
+_spack_docs() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_edit () {
+_spack_edit() {
     if $list_options
     then
-        compgen -W "-h --help -b --build-system -c --command -d --docs -t --test -m --module -r --repo -N --namespace" -- "$cur"
+        SPACK_COMPREPLY="-h --help -b --build-system -c --command -d --docs -t --test -m --module -r --repo -N --namespace"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_env () {
+_spack_env() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "activate deactivate create remove rm list ls status st loads view" -- "$cur"
+        SPACK_COMPREPLY="activate deactivate create remove rm list ls status st loads view"
     fi
 }
 
-_spack_env_activate () {
+_spack_env_activate() {
     if $list_options
     then
-        compgen -W "-h --help --sh --csh -v --with-view -V --without-view -d --dir -p --prompt" -- "$cur"
+        SPACK_COMPREPLY="-h --help --sh --csh -v --with-view -V --without-view -d --dir -p --prompt"
     else
-        compgen -W "$(_environments)" -- "$cur"
+        _environments
     fi
 }
 
-_spack_env_deactivate () {
-    compgen -W "-h --help --sh --csh" -- "$cur"
+_spack_env_deactivate() {
+    SPACK_COMPREPLY="-h --help --sh --csh"
 }
 
-_spack_env_create () {
+_spack_env_create() {
     if $list_options
     then
-        compgen -W "-h --help -d --dir --without-view --with-view" -- "$cur"
+        SPACK_COMPREPLY="-h --help -d --dir --without-view --with-view"
+    else
+        _environments
     fi
 }
 
-_spack_env_remove () {
+_spack_env_remove() {
     if $list_options
     then
-        compgen -W "-h --help -y --yes-to-all" -- "$cur"
+        SPACK_COMPREPLY="-h --help -y --yes-to-all"
     else
-        compgen -W "$(_environments)" -- "$cur"
+        _environments
     fi
 }
 
-_spack_env_rm () {
-    # Alias to `spack env remove`
-    _spack_env_remove
+_spack_env_rm() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help -y --yes-to-all"
+    else
+        _environments
+    fi
 }
 
-_spack_env_list () {
-    compgen -W "-h --help" -- "$cur"
+_spack_env_list() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_env_ls () {
-    # Alias to `spack env list`
-    _spack_env_list
+_spack_env_ls() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_env_status () {
-    compgen -W "-h --help" -- "$cur"
+_spack_env_status() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_env_st () {
-    # Alias to `spack env status`
-    _spack_env_status
+_spack_env_st() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_env_loads () {
+_spack_env_loads() {
     if $list_options
     then
-        compgen -W "-h --help -m --module-type --input-only -p --prefix -x --exclude -r --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help -m --module-type --input-only -p --prefix -x --exclude -r --dependencies"
     else
-        compgen -W "$(_environments)" -- "$cur"
+        _environments
     fi
 }
 
-_spack_env_view () {
+_spack_env_view() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "regenerate enable disable" -- "$cur"
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_extensions () {
+_spack_extensions() {
     if $list_options
     then
-        compgen -W "-h --help -l --long -L --very-long -d --deps -p --paths -s --show -v --view" -- "$cur"
+        SPACK_COMPREPLY="-h --help -l --long -L --very-long -d --deps -p --paths -s --show -v --view"
     else
-        compgen -W "aspell go-bootstrap go icedtea jdk kim-api lua matlab mofem-cephas octave openjdk perl python r ruby rust tcl yorick" -- "$cur"
+        _extensions
     fi
 }
 
-_spack_fetch () {
+_spack_fetch() {
     if $list_options
     then
-        compgen -W "-h --help -n --no-checksum -m --missing -D --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help -n --no-checksum -m --missing -D --dependencies"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_find () {
+_spack_find() {
     if $list_options
     then
-        compgen -W "-h --help --format --json -d --deps -p --paths --groups --no-groups -l --long -L --very-long -t --tags -c --show-concretized -f --show-flags --show-full-compiler -x --explicit -X --implicit -u --unknown -m --missing -v --variants -M --only-missing --deprecated --only-deprecated -N --namespace --start-date --end-date" -- "$cur"
+        SPACK_COMPREPLY="-h --help --format --json -d --deps -p --paths --groups --no-groups -l --long -L --very-long -t --tags -c --show-concretized -f --show-flags --show-full-compiler -x --explicit -X --implicit -u --unknown -m --missing -v --variants -M --only-missing --deprecated --only-deprecated -N --namespace --start-date --end-date"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_flake8 () {
+_spack_flake8() {
     if $list_options
     then
-        compgen -W "-h --help -b --base -k --keep-temp -a --all -o --output -r --root-relative -U --no-untracked" -- "$cur"
+        SPACK_COMPREPLY="-h --help -b --base -k --keep-temp -a --all -o --output -r --root-relative -U --no-untracked"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_gpg () {
+_spack_gc() {
+    SPACK_COMPREPLY="-h --help -y --yes-to-all"
+}
+
+_spack_gpg() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "verify trust untrust sign create list init export" -- "$cur"
+        SPACK_COMPREPLY="verify trust untrust sign create list init export"
     fi
 }
 
-_spack_gpg_verify () {
+_spack_gpg_verify() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_gpg_trust () {
+_spack_gpg_trust() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_gpg_untrust () {
+_spack_gpg_untrust() {
     if $list_options
     then
-        compgen -W "-h --help --signing" -- "$cur"
+        SPACK_COMPREPLY="-h --help --signing"
     else
-        compgen -W "$(_keys)" -- "$cur"
+        _keys
     fi
 }
 
-_spack_gpg_sign () {
+_spack_gpg_sign() {
     if $list_options
     then
-        compgen -W "-h --help --output --key --clearsign" -- "$cur"
+        SPACK_COMPREPLY="-h --help --output --key --clearsign"
     else
-        compgen -W "$(installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_gpg_create () {
+_spack_gpg_create() {
     if $list_options
     then
-        compgen -W "-h --help --comment --expires --export" -- "$cur"
+        SPACK_COMPREPLY="-h --help --comment --expires --export"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_gpg_list () {
-    compgen -W "-h --help --trusted --signing" -- "$cur"
+_spack_gpg_list() {
+    SPACK_COMPREPLY="-h --help --trusted --signing"
 }
 
-_spack_gpg_init () {
-    compgen -W "-h --help" -- "$cur"
+_spack_gpg_init() {
+    SPACK_COMPREPLY="-h --help --from"
 }
 
-_spack_gpg_export () {
+_spack_gpg_export() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_keys)" -- "$cur"
+        _keys
     fi
 }
 
-_spack_graph () {
+_spack_graph() {
     if $list_options
     then
-        compgen -W "-h --help -a --ascii -d --dot -s --static -i --installed --deptype" -- "$cur"
+        SPACK_COMPREPLY="-h --help -a --ascii -d --dot -s --static -i --installed --deptype"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_help () {
+_spack_help() {
     if $list_options
     then
-        compgen -W "-h --help -a --all --spec" -- "$cur"
+        SPACK_COMPREPLY="-h --help -a --all --spec"
     else
-        compgen -W "$(_subcommands)" -- "$cur"
+        _subcommands
     fi
 }
 
-_spack_info () {
+_spack_info() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_install () {
+_spack_install() {
     if $list_options
     then
-        compgen -W "-h --help --only -u --until -j --jobs --overwrite --keep-prefix --keep-stage --dont-restage --use-cache --no-cache --cache-only --show-log-on-error --source -n --no-checksum -v --verbose --fake --only-concrete -f --file --clean --dirty --test --run-tests --log-format --log-file --help-cdash -y --yes-to-all --cdash-upload-url --cdash-build --cdash-site --cdash-track --cdash-buildstamp" -- "$cur"
+        SPACK_COMPREPLY="-h --help --only -u --until -j --jobs --overwrite --keep-prefix --keep-stage --dont-restage --use-cache --no-cache --cache-only --show-log-on-error --source -n --no-checksum -v --verbose --fake --only-concrete -f --file --clean --dirty --test --run-tests --log-format --log-file --help-cdash --cdash-upload-url --cdash-build --cdash-site --cdash-track --cdash-buildstamp -y --yes-to-all"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_license () {
+_spack_license() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "list-files verify" -- "$cur"
+        SPACK_COMPREPLY="list-files verify"
     fi
 }
 
-_spack_license_list_files () {
-    compgen -W "-h --help" -- "$cur"
+_spack_license_list_files() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_license_verify () {
-    compgen -W "-h --help --root" -- "$cur"
+_spack_license_verify() {
+    SPACK_COMPREPLY="-h --help --root"
 }
 
-_spack_list () {
+_spack_list() {
     if $list_options
     then
-        compgen -W "-h --help -d --search-description --format --update -t --tags" -- "$cur"
+        SPACK_COMPREPLY="-h --help -d --search-description --format --update -t --tags"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_load () {
+_spack_load() {
     if $list_options
     then
-        compgen -W "-h --help -r --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help -r --dependencies"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_location () {
+_spack_location() {
     if $list_options
     then
-        compgen -W "-h --help -m --module-dir -r --spack-root -i --install-dir -p --package-dir -P --packages -s --stage-dir -S --stages -b --build-dir -e --env" -- "$cur"
+        SPACK_COMPREPLY="-h --help -m --module-dir -r --spack-root -i --install-dir -p --package-dir -P --packages -s --stage-dir -S --stages -b --build-dir -e --env"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_log_parse () {
+_spack_log_parse() {
     if $list_options
     then
-        compgen -W "-h --help --show -c --context -p --profile -w --width -j --jobs" -- "$cur"
+        SPACK_COMPREPLY="-h --help --show -c --context -p --profile -w --width -j --jobs"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_maintainers () {
+_spack_maintainers() {
     if $list_options
     then
-        compgen -W "-h --help --maintained --unmaintained -a --all --by-user" -- "$cur"
+        SPACK_COMPREPLY="-h --help --maintained --unmaintained -a --all --by-user"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_mirror () {
+_spack_mirror() {
     if $list_options
     then
-        compgen -W "-h --help -n --no-checksum" -- "$cur"
+        SPACK_COMPREPLY="-h --help -n --no-checksum"
     else
-        compgen -W "create add remove rm set-url list" -- "$cur"
+        SPACK_COMPREPLY="create add remove rm set-url list"
     fi
 }
 
-_spack_mirror_create () {
+_spack_mirror_create() {
     if $list_options
     then
-        compgen -W "-h --help -d --directory -a --all -f --file -D --dependencies -n --versions-per-spec" -- "$cur"
+        SPACK_COMPREPLY="-h --help -d --directory -a --all -f --file -D --dependencies -n --versions-per-spec"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_mirror_add () {
+_spack_mirror_add() {
     if $list_options
     then
-        compgen -W "-h --help --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --scope"
+    else
+        _mirrors
     fi
 }
 
-_spack_mirror_remove () {
+_spack_mirror_remove() {
     if $list_options
     then
-        compgen -W "-h --help --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --scope"
     else
-        compgen -W "$(_mirrors)" -- "$cur"
+        _mirrors
     fi
 }
 
-_spack_mirror_rm () {
-    # Alias to `spack mirror remove`
-    _spack_mirror_remove
+_spack_mirror_rm() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help --scope"
+    else
+        _mirrors
+    fi
 }
 
-_spack_mirror_set_url () {
+_spack_mirror_set_url() {
     if $list_options
     then
-        compgen -W "-h --help --push --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --push --scope"
     else
-        compgen -W "$(_mirrors)" -- "$cur"
+        _mirrors
     fi
 }
 
-_spack_mirror_list () {
-    compgen -W "-h --help --scope" -- "$cur"
+_spack_mirror_list() {
+    SPACK_COMPREPLY="-h --help --scope"
 }
 
-_spack_module () {
+_spack_module() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "lmod tcl" -- "$cur"
+        SPACK_COMPREPLY="lmod tcl"
     fi
 }
 
-_spack_module_lmod () {
+_spack_module_lmod() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "refresh find rm loads setdefault" -- "$cur"
+        SPACK_COMPREPLY="refresh find rm loads setdefault"
     fi
 }
 
-_spack_module_lmod_refresh () {
+_spack_module_lmod_refresh() {
     if $list_options
     then
-        compgen -W "-h --help --delete-tree --upstream-modules -y --yes-to-all" -- "$cur"
+        SPACK_COMPREPLY="-h --help --delete-tree --upstream-modules -y --yes-to-all"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_module_lmod_find () {
+_spack_module_lmod_find() {
     if $list_options
     then
-        compgen -W "-h --help --full-path -r --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help --full-path -r --dependencies"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_module_lmod_rm () {
+_spack_module_lmod_rm() {
     if $list_options
     then
-        compgen -W "-h --help -y --yes-to-all" -- "$cur"
+        SPACK_COMPREPLY="-h --help -y --yes-to-all"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_module_lmod_loads () {
+_spack_module_lmod_loads() {
     if $list_options
     then
-        compgen -W "-h --help --input-only -p --prefix -x --exclude -r --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help --input-only -p --prefix -x --exclude -r --dependencies"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
-
 }
 
-_spack_module_lmod_setdefault () {
+_spack_module_lmod_setdefault() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_module_tcl () {
+_spack_module_tcl() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "refresh find rm loads" -- "$cur"
+        SPACK_COMPREPLY="refresh find rm loads"
     fi
 }
 
-_spack_module_tcl_refresh () {
+_spack_module_tcl_refresh() {
     if $list_options
     then
-        compgen -W "-h --help --delete-tree --upstream-modules -y --yes-to-all" -- "$cur"
+        SPACK_COMPREPLY="-h --help --delete-tree --upstream-modules -y --yes-to-all"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_module_tcl_find () {
+_spack_module_tcl_find() {
     if $list_options
     then
-        compgen -W "-h --help --full-path -r --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help --full-path -r --dependencies"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_module_tcl_rm () {
+_spack_module_tcl_rm() {
     if $list_options
     then
-        compgen -W "-h --help -y --yes-to-all" -- "$cur"
+        SPACK_COMPREPLY="-h --help -y --yes-to-all"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_module_tcl_loads () {
+_spack_module_tcl_loads() {
     if $list_options
     then
-        compgen -W "-h --help --input-only -p --prefix -x --exclude -r --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help --input-only -p --prefix -x --exclude -r --dependencies"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_patch () {
+_spack_patch() {
     if $list_options
     then
-        compgen -W "-h --help -n --no-checksum" -- "$cur"
+        SPACK_COMPREPLY="-h --help -n --no-checksum"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_pkg () {
+_spack_pkg() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "add list diff added changed removed" -- "$cur"
+        SPACK_COMPREPLY="add list diff added changed removed"
     fi
 }
 
-_spack_pkg_add () {
+_spack_pkg_add() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_pkg_list () {
-    # FIXME: How to list git revisions?
+_spack_pkg_list() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_pkg_diff () {
-    # FIXME: How to list git revisions?
+_spack_pkg_diff() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_pkg_added () {
-    # FIXME: How to list git revisions?
+_spack_pkg_added() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_pkg_changed () {
-    # FIXME: How to list git revisions?
+_spack_pkg_changed() {
     if $list_options
     then
-        compgen -W "-h --help -t --type" -- "$cur"
+        SPACK_COMPREPLY="-h --help -t --type"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_pkg_removed () {
-    # FIXME: How to list git revisions?
+_spack_pkg_removed() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_providers () {
+_spack_providers() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_providers)" -- "$cur"
+        _providers
     fi
 }
 
-_spack_pydoc () {
+_spack_pydoc() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_python () {
+_spack_python() {
     if $list_options
     then
-        compgen -W "-h --help -c" -- "$cur"
+        SPACK_COMPREPLY="-h --help -c"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_reindex () {
-    compgen -W "-h --help" -- "$cur"
+_spack_reindex() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_release_jobs () {
-    compgen -W "-h --help -o --output-file -p --print-summary --cdash-credentials" -- "$cur"
+_spack_remove() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help -a --all -l --list-name -f --force"
+    else
+        _all_packages
+    fi
 }
 
-_spack_remove () {
+_spack_rm() {
     if $list_options
     then
-        compgen -W "-h --help -a --all -l --list-name -f --force" -- "$cur"
+        SPACK_COMPREPLY="-h --help -a --all -l --list-name -f --force"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_repo () {
+_spack_repo() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "create list add remove rm" -- "$cur"
+        SPACK_COMPREPLY="create list add remove rm"
     fi
 }
 
-_spack_repo_create () {
+_spack_repo_create() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
+    else
+        _repos
     fi
 }
 
-_spack_repo_list () {
-    compgen -W "-h --help --scope" -- "$cur"
+_spack_repo_list() {
+    SPACK_COMPREPLY="-h --help --scope"
 }
 
-_spack_repo_add () {
+_spack_repo_add() {
     if $list_options
     then
-        compgen -W "-h --help --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --scope"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_repo_remove () {
+_spack_repo_remove() {
     if $list_options
     then
-        compgen -W "-h --help --scope" -- "$cur"
+        SPACK_COMPREPLY="-h --help --scope"
     else
-        compgen -W "$(_repos)" -- "$cur"
+        _repos
     fi
 }
 
-_spack_repo_rm () {
-    # Alias to `spack repo remove`
-    _spack_repo_remove
+_spack_repo_rm() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help --scope"
+    else
+        _repos
+    fi
 }
 
-_spack_resource () {
+_spack_resource() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "list show" -- "$cur"
+        SPACK_COMPREPLY="list show"
     fi
 }
 
-_spack_resource_list () {
-    compgen -W "-h --help --only-hashes" -- "$cur"
+_spack_resource_list() {
+    SPACK_COMPREPLY="-h --help --only-hashes"
 }
 
-_spack_resource_show () {
+_spack_resource_show() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_all_resource_hashes)" -- "$cur"
+        _all_resource_hashes
     fi
 }
 
-_spack_restage () {
+_spack_restage() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_setup () {
+_spack_setup() {
     if $list_options
     then
-        compgen -W "-h --help -i --ignore-dependencies -n --no-checksum -v --verbose --clean --dirty" -- "$cur"
+        SPACK_COMPREPLY="-h --help -i --ignore-dependencies -n --no-checksum -v --verbose --clean --dirty"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_spec () {
+_spack_spec() {
     if $list_options
     then
-        compgen -W "-h --help -l --long -L --very-long -I --install-status -y --yaml -j --json -c --cover -N --namespaces -t --types" -- "$cur"
+        SPACK_COMPREPLY="-h --help -l --long -L --very-long -I --install-status -y --yaml -j --json -c --cover -N --namespaces -t --types"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_stage () {
+_spack_stage() {
     if $list_options
     then
-        compgen -W "-h --help -n --no-checksum -p --path" -- "$cur"
+        SPACK_COMPREPLY="-h --help -n --no-checksum -p --path"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_test () {
+_spack_test() {
     if $list_options
     then
-        compgen -W "-h --help -H --pytest-help --extension -l --list -L --list-long -N --list-names -s -k --showlocals" -- "$cur"
+        SPACK_COMPREPLY="-h --help -H --pytest-help -l --list -L --list-long -N --list-names --extension -s -k --showlocals"
     else
-        compgen -W "$(_tests)" -- "$cur"
+        _tests
     fi
 }
 
-_spack_uninstall () {
+_spack_uninstall() {
     if $list_options
     then
-        compgen -W "-h --help -f --force -R --dependents -y --yes-to-all -a --all" -- "$cur"
+        SPACK_COMPREPLY="-h --help -f --force -R --dependents -y --yes-to-all -a --all"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_unload () {
+_spack_unload() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "$(_installed_packages)" -- "$cur"
+        _installed_packages
     fi
 }
 
-_spack_upload_s3 () {
+_spack_upload_s3() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "spec index" -- "$cur"
+        SPACK_COMPREPLY="spec index"
     fi
 }
 
-_spack_upload_s3_spec () {
-    compgen -W "-h --help -s --spec -y --spec-yaml -b --base-dir -e --endpoint-url" -- "$cur"
+_spack_upload_s3_spec() {
+    SPACK_COMPREPLY="-h --help -s --spec -y --spec-yaml -b --base-dir -e --endpoint-url"
 }
 
-_spack_upload_s3_index () {
-    compgen -W "-h --help -e --endpoint-url" -- "$cur"
+_spack_upload_s3_index() {
+    SPACK_COMPREPLY="-h --help -e --endpoint-url"
 }
 
-_spack_url () {
+_spack_url() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help"
     else
-        compgen -W "parse list summary stats" -- "$cur"
+        SPACK_COMPREPLY="parse list summary stats"
     fi
 }
 
-_spack_url_parse () {
+_spack_url_parse() {
     if $list_options
     then
-        compgen -W "-h --help -s --spider" -- "$cur"
+        SPACK_COMPREPLY="-h --help -s --spider"
+    else
+        SPACK_COMPREPLY=""
     fi
 }
 
-_spack_url_list () {
-    compgen -W "-h --help -c --color -e --extrapolation -n --incorrect-name -N --correct-name -v --incorrect-version -V --correct-version" -- "$cur"
+_spack_url_list() {
+    SPACK_COMPREPLY="-h --help -c --color -e --extrapolation -n --incorrect-name -N --correct-name -v --incorrect-version -V --correct-version"
 }
 
-_spack_url_summary () {
-    compgen -W "-h --help" -- "$cur"
+_spack_url_summary() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_url_stats () {
-    compgen -W "-h --help" -- "$cur"
+_spack_url_stats() {
+    SPACK_COMPREPLY="-h --help"
 }
 
-_spack_verify () {
+_spack_verify() {
     if $list_options
     then
-        compgen -W "-h --help -l --local -j --json -a --all -s --specs -f --files" -- "$cur"
+        SPACK_COMPREPLY="-h --help -l --local -j --json -a --all -s --specs -f --files"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_versions () {
+_spack_versions() {
     if $list_options
     then
-        compgen -W "-h --help -s --safe-only" -- "$cur"
+        SPACK_COMPREPLY="-h --help -s --safe-only"
     else
-        compgen -W "$(_all_packages)" -- "$cur"
+        _all_packages
     fi
 }
 
-_spack_view () {
+_spack_view() {
     if $list_options
     then
-        compgen -W "-h --help -v --verbose -e --exclude -d --dependencies" -- "$cur"
+        SPACK_COMPREPLY="-h --help -v --verbose -e --exclude -d --dependencies"
     else
-        compgen -W "symlink add soft hardlink hard remove rm statlink status check" -- "$cur"
+        SPACK_COMPREPLY="symlink add soft hardlink hard remove rm statlink status check"
     fi
 }
 
-_spack_view_symlink () {
+_spack_view_symlink() {
     if $list_options
     then
-        compgen -W "-h --help --projection-file -i --ignore-conflicts" -- "$cur"
+        SPACK_COMPREPLY="-h --help --projection-file -i --ignore-conflicts"
+    else
+        _all_packages
     fi
 }
 
-_spack_view_add () {
-    # Alias for `spack view symlink`
-    _spack_view_symlink
-}
-
-_spack_view_soft () {
-    # Alias for `spack view symlink`
-    _spack_view_symlink
-}
-
-_spack_view_hardlink () {
+_spack_view_add() {
     if $list_options
     then
-        compgen -W "-h --help --projection-file -i --ignore-conflicts" -- "$cur"
+        SPACK_COMPREPLY="-h --help --projection-file -i --ignore-conflicts"
+    else
+        _all_packages
     fi
 }
 
-_spack_view_hard () {
-    # Alias for `spack view hardlink`
-    _spack_view_hardlink
-}
-
-_spack_view_remove () {
+_spack_view_soft() {
     if $list_options
     then
-        compgen -W "-h --help --no-remove-dependents -a --all" -- "$cur"
+        SPACK_COMPREPLY="-h --help --projection-file -i --ignore-conflicts"
+    else
+        _all_packages
     fi
 }
 
-_spack_view_rm () {
-    # Alias for `spack view remove`
-    _spack_view_remove
-}
-
-_spack_view_statlink () {
+_spack_view_hardlink() {
     if $list_options
     then
-        compgen -W "-h --help" -- "$cur"
+        SPACK_COMPREPLY="-h --help --projection-file -i --ignore-conflicts"
+    else
+        _all_packages
     fi
 }
 
-_spack_view_status () {
-    # Alias for `spack view statlink`
-    _spack_view_statlink
-}
-
-_spack_view_check () {
-    # Alias for `spack view statlink`
-    _spack_view_statlink
-}
-
-# Helper functions for subcommands
-
-_subcommands () {
-    spack commands
-}
-
-_all_packages () {
-    spack list
-}
-
-_all_resource_hashes () {
-    spack resource list --only-hashes
-}
-
-_installed_packages () {
-    spack --color=never find --no-groups
-}
-
-_installed_compilers () {
-    spack compilers | egrep -v "^(-|=)"
-}
-
-_providers () {
-    spack providers
-}
-
-_mirrors () {
-    spack mirror list | awk '{print $1}'
-}
-
-_repos () {
-    spack repo list | awk '{print $1}'
+_spack_view_hard() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help --projection-file -i --ignore-conflicts"
+    else
+        _all_packages
+    fi
 }
 
-_tests () {
-    spack test -l
+_spack_view_remove() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help --no-remove-dependents -a --all"
+    else
+        _all_packages
+    fi
 }
 
-_environments () {
-    spack env list
+_spack_view_rm() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help --no-remove-dependents -a --all"
+    else
+        _all_packages
+    fi
 }
 
-_keys () {
-    spack gpg list
+_spack_view_statlink() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help"
+    else
+        _all_packages
+    fi
 }
 
-# Testing functions
-
-_test_vars () {
-    echo "-----------------------------------------------------"             >> temp
-    echo "Full line:                '$COMP_LINE'"                            >> temp
-    echo                                                                     >> temp
-    echo "Word list w/ flags:       $(_pretty_print COMP_WORDS[@])"          >> temp
-    echo "# words w/ flags:         '${#COMP_WORDS[@]}'"                     >> temp
-    echo "Cursor index w/ flags:    '$COMP_CWORD'"                           >> temp
-    echo                                                                     >> temp
-    echo "Word list w/out flags:    $(_pretty_print COMP_WORDS_NO_FLAGS[@])" >> temp
-    echo "# words w/out flags:      '${#COMP_WORDS_NO_FLAGS[@]}'"            >> temp
-    echo "Cursor index w/out flags: '$COMP_CWORD_NO_FLAGS'"                  >> temp
-    echo                                                                     >> temp
-    echo "Subfunction:              '$subfunction'"                          >> temp
+_spack_view_status() {
     if $list_options
     then
-        echo "List options:             'True'"  >> temp
+        SPACK_COMPREPLY="-h --help"
     else
-        echo "List options:             'False'" >> temp
+        _all_packages
     fi
-    echo "Current word:             '$cur'"  >> temp
-    echo "Previous word:            '$prev'" >> temp
 }
 
-# Pretty-prints one or more arrays
-# Syntax: _pretty_print array1[@] ...
-_pretty_print () {
-    for arg in $@
-    do
-        local array=("${!arg}")
-        echo -n "$arg: ["
-        printf   "'%s'" "${array[0]}"
-        printf ", '%s'" "${array[@]:1}"
-        echo "]"
-    done
+_spack_view_check() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help"
+    else
+        _all_packages
+    fi
 }
-
-complete -o default -F _bash_completion_spack spack