EOF
guix package -A emacs-foo-bar -L "$module_dir" | grep 42
-guix package -i emacs-foo-bar-42 -n -L "$module_dir"
+guix package -i emacs-foo-bar@42 -n -L "$module_dir"
# Same thing using the 'GUIX_PACKAGE_PATH' environment variable.
GUIX_PACKAGE_PATH="$module_dir"
export GUIX_PACKAGE_PATH
guix package -A emacs-foo-bar | grep 42
-guix package -i emacs-foo-bar-42 -n
+guix package -i emacs-foo-bar@42 -n
# Make sure patches that live under $GUIX_PACKAGE_PATH are found.
cat > "$module_dir/emacs.patch"<<EOF