info: rework spack info command to display variants better (#40998)

This changes variant display to use a much more legible format, and to use screen space
much better (particularly on narrow terminals). It also adds color the variant display
to match other parts of `spack info`.

Descriptions and variant value lists that were frequently squished into a tiny column
before now have closer to the full terminal width.

This change also preserves any whitespace formatting present in `package.py`, so package
maintainers can make easer-to-read descriptions of variant values if they want. For
example, `gasnet` has had a nice description of the `conduits` variant for a while, but
it was wrapped and made illegible by `spack info`. That is now fixed and the original
newlines are kept.

Conditional variants are grouped by their when clauses by default, but if you do not
like the grouping, you can display all the variants in order with `--variants-by-name`.
I'm not sure when people will prefer this, but it makes it easier to tell that a
particular variant is/isn't there. I do think grouping by `when` is the better default.

2 files changed, 4 insertions, 2 deletions

diff --git a/share/spack/spack-completion.bash b/share/spack/spack-completion.bash
index 20bb886b10..e84fe10134 100755
--- a/share/spack/spack-completion.bash
+++ b/share/spack/spack-completion.bash
@@ -1267,7 +1267,7 @@ _spack_help() {
 _spack_info() {
     if $list_options
     then
-        SPACK_COMPREPLY="-h --help -a --all --detectable --maintainers --no-dependencies --no-variants --no-versions --phases --tags --tests --virtuals"
+        SPACK_COMPREPLY="-h --help -a --all --detectable --maintainers --no-dependencies --no-variants --no-versions --phases --tags --tests --virtuals --variants-by-name"
     else
         _all_packages
     fi
diff --git a/share/spack/spack-completion.fish b/share/spack/spack-completion.fish
index 769768c04c..d660c251af 100755
--- a/share/spack/spack-completion.fish
+++ b/share/spack/spack-completion.fish
@@ -1855,7 +1855,7 @@ complete -c spack -n '__fish_spack_using_command help' -l spec -f -a guide
 complete -c spack -n '__fish_spack_using_command help' -l spec -d 'help on the package specification syntax'
 
 # spack info
-set -g __fish_spack_optspecs_spack_info h/help a/all detectable maintainers no-dependencies no-variants no-versions phases tags tests virtuals
+set -g __fish_spack_optspecs_spack_info h/help a/all detectable maintainers no-dependencies no-variants no-versions phases tags tests virtuals variants-by-name
 complete -c spack -n '__fish_spack_using_command_pos 0 info' -f -a '(__fish_spack_packages)'
 complete -c spack -n '__fish_spack_using_command info' -s h -l help -f -a help
 complete -c spack -n '__fish_spack_using_command info' -s h -l help -d 'show this help message and exit'
@@ -1879,6 +1879,8 @@ complete -c spack -n '__fish_spack_using_command info' -l tests -f -a tests
 complete -c spack -n '__fish_spack_using_command info' -l tests -d 'output relevant build-time and stand-alone tests'
 complete -c spack -n '__fish_spack_using_command info' -l virtuals -f -a virtuals
 complete -c spack -n '__fish_spack_using_command info' -l virtuals -d 'output virtual packages'
+complete -c spack -n '__fish_spack_using_command info' -l variants-by-name -f -a variants_by_name
+complete -c spack -n '__fish_spack_using_command info' -l variants-by-name -d 'list variants in strict name order; don\'t group by condition'
 
 # spack install
 set -g __fish_spack_optspecs_spack_install h/help only= u/until= j/jobs= overwrite fail-fast keep-prefix keep-stage dont-restage use-cache no-cache cache-only use-buildcache= include-build-deps no-check-signature show-log-on-error source n/no-checksum deprecated v/verbose fake only-concrete add no-add f/file= clean dirty test= log-format= log-file= help-cdash cdash-upload-url= cdash-build= cdash-site= cdash-track= cdash-buildstamp= y/yes-to-all U/fresh reuse reuse-deps