Add missing dependencies for Flake8 (#1883)

* Warn user if flake8 can't find setuptools

* Add missing dependencies of flake8

* Updates to py-autopep8, make packages activateable

* Check for presence of setuptools for Sphinx too

* Fix bug in order of commands

2 files changed, 30 insertions, 4 deletions

diff --git a/share/spack/qa/check_dependencies b/share/spack/qa/check_dependencies
index cf3d204f48..e999463b03 100755
--- a/share/spack/qa/check_dependencies
+++ b/share/spack/qa/check_dependencies
@@ -65,6 +65,32 @@ for dep in "$@"; do
 
         exit 1
     fi
+
+    # Flake8 and Sphinx require setuptools in order to run.
+    # Otherwise, they print out this error message:
+    #
+    #   Traceback (most recent call last):
+    #     File: "/usr/bin/flake8", line 5, in <module>
+    #       from pkg_resources import load_entry_point
+    #   ImportError: No module named pkg_resources
+    #
+    # Print a more useful error message if setuptools not found.
+    if [[ $dep == flake8 || $dep == sphinx* ]]; then
+        # Find which Python is being run
+        # Spack-installed packages have a hard-coded shebang
+        python_cmd=$(head -n 1 $(which $dep) | cut -c 3-)
+        # May not have a shebang
+        if [[ $python_cmd != *python* ]]; then
+            python_cmd=python
+        fi
+        # Check if setuptools is in the PYTHONPATH
+        if ! $python_cmd -c "import setuptools" 2> /dev/null; then
+            echo "ERROR: setuptools is required to run $dep."
+            echo "Please add it to your PYTHONPATH."
+
+            exit 1
+        fi
+    fi
 done
 
 echo "Dependencies found."
diff --git a/share/spack/qa/run-flake8-tests b/share/spack/qa/run-flake8-tests
index 350ef3161f..6fe97160e3 100755
--- a/share/spack/qa/run-flake8-tests
+++ b/share/spack/qa/run-flake8-tests
@@ -23,10 +23,6 @@ deps=(
 # Check for dependencies
 "$QA_DIR/check_dependencies" "${deps[@]}" || exit 1
 
-# Move to root directory of Spack
-# Allows script to be run from anywhere
-cd "$SPACK_ROOT"
-
 # Gather array of changed files
 changed=($("$QA_DIR/changed_files" "*.py"))
 
@@ -36,6 +32,10 @@ if [[ ! "${changed[@]}" ]]; then
     exit 0
 fi
 
+# Move to root directory of Spack
+# Allows script to be run from anywhere
+cd "$SPACK_ROOT"
+
 function cleanup {
     # Restore original package files after modifying them.
     for file in "${changed[@]}"; do