`spack deconcretize` command (#38803)

We have two ways to concretize now:
* `spack concretize` concretizes only the root specs that are not concrete in the environment.
* `spack concretize -f` eliminates all cached concretization data and reconcretizes the *entire* environment.

This PR adds `spack deconcretize`, which eliminates cached concretization data for a spec.  This allows
users greater control over what is preserved from their `spack.lock` file and what is reused when not
using `spack concretize -f`.  If you want to update a spec installed in your environment, you can call
`spack deconcretize` on it, and that spec and any relevant dependents will be removed from the lock file.

`spack concretize` has two options:
* `--root`: limits deconcretized specs to *specific* roots in the environment. You can use this to
  deconcretize exactly one root in a `unify: false` environment.  i.e., if `foo` root is a dependent
  of `bar`, both roots, `spack deconcretize bar` will *not* deconcretize `foo`.
* `--all`: deconcretize *all* specs that match the input spec. By default `spack deconcretize`
  will complain about multiple matches, like `spack uninstall`.

2 files changed, 23 insertions, 1 deletions

diff --git a/share/spack/spack-completion.bash b/share/spack/spack-completion.bash
index e84fe10134..a54f7db414 100755
--- a/share/spack/spack-completion.bash
+++ b/share/spack/spack-completion.bash
@@ -401,7 +401,7 @@ _spack() {
     then
         SPACK_COMPREPLY="-h --help -H --all-help --color -c --config -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 -b --bootstrap -p --profile --sorted-profile --lines -v --verbose --stacktrace --backtrace -V --version --print-shell-vars"
     else
-        SPACK_COMPREPLY="add arch audit blame bootstrap build-env buildcache cd change checksum ci clean clone commands compiler compilers concretize concretise config containerize containerise create debug dependencies dependents deprecate dev-build develop diff docs edit env extensions external fetch find gc gpg graph help info install license list load location log-parse maintainers make-installer mark mirror module patch pkg providers pydoc python reindex remove rm repo resource restage solve spec stage style tags test test-env tutorial undevelop uninstall unit-test unload url verify versions view"
+        SPACK_COMPREPLY="add arch audit blame bootstrap build-env buildcache cd change checksum ci clean clone commands compiler compilers concretize concretise config containerize containerise create debug deconcretize dependencies dependents deprecate dev-build develop diff docs edit env extensions external fetch find gc gpg graph help info install license list load location log-parse maintainers make-installer mark mirror module patch pkg providers pydoc python reindex remove rm repo resource restage solve spec stage style tags test test-env tutorial undevelop uninstall unit-test unload url verify versions view"
     fi
 }
 
@@ -937,6 +937,15 @@ _spack_debug_report() {
     SPACK_COMPREPLY="-h --help"
 }
 
+_spack_deconcretize() {
+    if $list_options
+    then
+        SPACK_COMPREPLY="-h --help --root -y --yes-to-all -a --all"
+    else
+        _all_packages
+    fi
+}
+
 _spack_dependencies() {
     if $list_options
     then
diff --git a/share/spack/spack-completion.fish b/share/spack/spack-completion.fish
index d660c251af..1029fa6b45 100755
--- a/share/spack/spack-completion.fish
+++ b/share/spack/spack-completion.fish
@@ -371,6 +371,7 @@ complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a containerize -d '
 complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a containerise -d 'creates recipes to build images for different container runtimes'
 complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a create -d 'create a new package file'
 complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a debug -d 'debugging commands for troubleshooting Spack'
+complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a deconcretize -d 'remove specs from the concretized lockfile of an environment'
 complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a dependencies -d 'show dependencies of a package'
 complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a dependents -d 'show packages that depend on another'
 complete -c spack -n '__fish_spack_using_command_pos 0 ' -f -a deprecate -d 'replace one package with another via symlinks'
@@ -1290,6 +1291,18 @@ set -g __fish_spack_optspecs_spack_debug_report h/help
 complete -c spack -n '__fish_spack_using_command debug report' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command debug report' -s h -l help -d 'show this help message and exit'
 
+# spack deconcretize
+set -g __fish_spack_optspecs_spack_deconcretize h/help root y/yes-to-all a/all
+complete -c spack -n '__fish_spack_using_command_pos_remainder 0 deconcretize' -f -k -a '(__fish_spack_specs)'
+complete -c spack -n '__fish_spack_using_command deconcretize' -s h -l help -f -a help
+complete -c spack -n '__fish_spack_using_command deconcretize' -s h -l help -d 'show this help message and exit'
+complete -c spack -n '__fish_spack_using_command deconcretize' -l root -f -a root
+complete -c spack -n '__fish_spack_using_command deconcretize' -l root -d 'deconcretize only specific environment roots'
+complete -c spack -n '__fish_spack_using_command deconcretize' -s y -l yes-to-all -f -a yes_to_all
+complete -c spack -n '__fish_spack_using_command deconcretize' -s y -l yes-to-all -d 'assume "yes" is the answer to every confirmation request'
+complete -c spack -n '__fish_spack_using_command deconcretize' -s a -l all -f -a all
+complete -c spack -n '__fish_spack_using_command deconcretize' -s a -l all -d 'deconcretize ALL specs that match each supplied spec'
+
 # spack dependencies
 set -g __fish_spack_optspecs_spack_dependencies h/help i/installed t/transitive deptype= V/no-expand-virtuals
 complete -c spack -n '__fish_spack_using_command_pos_remainder 0 dependencies' -f -k -a '(__fish_spack_specs)'