[rubygems/rubygems] Improve "gem not found in source" errors

When printing sources inside these error messages, it's useful to only
consider the current state of the source. For example, when requiring
`bundler/setup`, the source shouldn't be configured to be able to hit
the network, so the error message should only mention "locally installed
gems" to make that more clear.

https://github.com/rubygems/rubygems/commit/30eb14f853

2 files changed, 20 insertions, 1 deletions

diff --git a/lib/bundler/source/rubygems.rb b/lib/bundler/source/rubygems.rb
index 858a69a48b..6728ffdc63 100644
--- a/lib/bundler/source/rubygems.rb
+++ b/lib/bundler/source/rubygems.rb
@@ -96,11 +96,22 @@ module Bundler
         out << "  specs:\n"
       end
 
+      def to_err
+        if remotes.empty?
+          "locally installed gems"
+        elsif @allow_remote
+          "rubygems repository #{remote_names} or installed locally"
+        elsif @allow_cached
+          "cached gems from rubygems repository #{remote_names} or installed locally"
+        else
+          "locally installed gems"
+        end
+      end
+
       def to_s
         if remotes.empty?
           "locally installed gems"
         else
-          remote_names = remotes.map(&:to_s).join(", ")
           "rubygems repository #{remote_names} or installed locally"
         end
       end
@@ -319,6 +330,10 @@ module Bundler
 
       protected
 
+      def remote_names
+        remotes.map(&:to_s).join(", ")
+      end
+
       def credless_remotes
         remotes.map(&method(:suppress_configured_credentials))
       end
diff --git a/lib/bundler/source/rubygems_aggregate.rb b/lib/bundler/source/rubygems_aggregate.rb
index 685bf7e90a..09cf4002ea 100644
--- a/lib/bundler/source/rubygems_aggregate.rb
+++ b/lib/bundler/source/rubygems_aggregate.rb
@@ -16,6 +16,10 @@ module Bundler
         @index
       end
 
+      def to_err
+        to_s
+      end
+
       def to_s
         "any of the sources"
       end