[gentoo-dev] [PATCH] ruby-single.eclass: depend on virtual/rubygems[ruby_targets_rubyNN(-)] for each impl

[Sam James]

Noticed when looking at bug 771744 which seems hard to trigger deliberately -
the webkit-gtk ebuild already tries to check the chosen Ruby has rubygems 
available.

Anyway, when looking at that, I noticed it's possible for Portage to queue
the following, even if it's not what's happening in this case:
- dev-lang/ruby:2.7 is already installed
- virtual/rubygems[ruby_targets_ruby27] is already installed (PDEPEND of ruby)
and then, in a fresh emerge:
- dev-lang/ruby:3.0 is installed
- app-misc/foo (with only USE_RUBY="ruby30") using ruby-single.eclass is queued
  and fails because the installed Ruby isn't fully usable yet, because
  the eclass only guarantees dev-lang/ruby:3.0 and virtual/rubygems is 
installed,
  not necessarily rubygems for that interpreter.
- virtual/rubygems[ruby_targets_ruby30] is built (PDEPEND of ruby)

This isn't a subsittute for a ruby-any.eclass and/or a pkg_setup which helps
enforcement, but that's another thing to handle.

Followup to d078ec2a151d16b7ed045f1889bb5b97c4b9e6af ("Add virtual/rubygems to 
dependencies[...]").

Bug: https://bugs.gentoo.org/771744
Signed-off-by: Sam James <s...@gentoo.org>
---
 eclass/ruby-single.eclass | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/eclass/ruby-single.eclass b/eclass/ruby-single.eclass
index 035675c4810a0..5f6cf9e46dcee 100644
--- a/eclass/ruby-single.eclass
+++ b/eclass/ruby-single.eclass
@@ -1,4 +1,4 @@
-# Copyright 1999-2022 Gentoo Authors
+# Copyright 1999-2023 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 # @ECLASS: ruby-single.eclass
@@ -72,10 +72,13 @@ _ruby_single_implementations_depend() {
        local depend
        for _ruby_implementation in ${RUBY_TARGETS_PREFERENCE}; do
                if [[ ${USE_RUBY} =~ ${_ruby_implementation} ]]; then
-                       depend="${depend} $(_ruby_implementation_depend 
$_ruby_implementation)"
+                       depend+=" ("
+                       depend+=" $(_ruby_implementation_depend 
$_ruby_implementation)"
+                       depend+=" 
virtual/rubygems[ruby_targets_${_ruby_implementation}(-)]"
+                       depend+=" )"
                fi
        done
-       echo "|| ( ${depend} ) virtual/rubygems"
+       echo "|| ( ${depend} )"
 }
 
 _ruby_single_set_globals() {
-- 
2.40.0