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.

bundler/lib/bundler/resolver.rb

@@ -272,7 +272,7 @@ def verify_gemfile_dependencies_are_found!(requirements)
                             rescue GemfileNotFound
                               nil
                             end
-          message = String.new("Could not find gem '#{SharedHelpers.pretty_dependency(requirement)}' in #{source}#{cache_message}.\n")
+          message = String.new("Could not find gem '#{SharedHelpers.pretty_dependency(requirement)}' in #{source.to_err}#{cache_message}.\n")
           message << "The source contains the following versions of '#{name}': #{formatted_versions_with_platforms(versions_with_platforms)}" if versions_with_platforms.any?
         end
         raise GemNotFound, message
@@ -371,7 +371,7 @@ def version_conflict_message(e)
             o << if metadata_requirement
               "is not available in #{relevant_source}"
             else
-              "in #{relevant_source}.\n"
+              "in #{relevant_source.to_err}.\n"
             end
           end
         end,

bundler/lib/bundler/source.rb

@@ -67,6 +67,10 @@ def inspect
       "#<#{self.class}:0x#{object_id} #{self}>"
     end
 
+    def to_err
+      to_s
+    end
+
     def path?
       instance_of?(Bundler::Source::Path)
     end

bundler/lib/bundler/source/rubygems.rb

@@ -96,11 +96,22 @@ def to_lock
         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 @@ def dependency_api_available?
 
       protected
 
+      def remote_names
+        remotes.map(&:to_s).join(", ")
+      end
+
       def credless_remotes
         remotes.map(&method(:suppress_configured_credentials))
       end

bundler/lib/bundler/source/rubygems_aggregate.rb

@@ -16,6 +16,10 @@ def specs
         @index
       end
 
+      def to_err
+        to_s
+      end
+
       def to_s
         "any of the sources"
       end

bundler/spec/commands/exec_spec.rb

@@ -836,7 +836,7 @@ def bin_path(a,b,c)
       let(:exit_code) { Bundler::GemNotFound.new.status_code }
       let(:expected) { "" }
       let(:expected_err) { <<-EOS.strip }
-Could not find gem 'rack (= 2)' in rubygems repository #{file_uri_for(gem_repo1)}/ or installed locally.
+Could not find gem 'rack (= 2)' in locally installed gems.
 The source contains the following versions of 'rack': 0.9.1, 1.0.0
 Run `bundle install` to install missing gems.
       EOS
@@ -863,7 +863,7 @@ def bin_path(a,b,c)
       let(:exit_code) { Bundler::GemNotFound.new.status_code }
       let(:expected) { "" }
       let(:expected_err) { <<-EOS.strip }
-Could not find gem 'rack (= 2)' in rubygems repository #{file_uri_for(gem_repo1)}/ or installed locally.
+Could not find gem 'rack (= 2)' in locally installed gems.
 The source contains the following versions of 'rack': 1.0.0
 Run `bundle install` to install missing gems.
       EOS

bundler/spec/commands/lock_spec.rb

@@ -86,7 +86,7 @@ def read_lockfile(file = "Gemfile.lock")
   it "does not fetch remote specs when using the --local option" do
     bundle "lock --update --local", :raise_on_error => false
 
-    expect(err).to match(/installed locally/)
+    expect(err).to match(/locally installed gems/)
   end
 
   it "works with --gemfile flag" do

bundler/spec/support/indexes.rb

@@ -17,7 +17,7 @@ def platform(*args)
     def resolve(args = [])
       @platforms ||= ["ruby"]
       deps = []
-      default_source = instance_double("Bundler::Source::Rubygems", :specs => @index)
+      default_source = instance_double("Bundler::Source::Rubygems", :specs => @index, :to_err => "locally install gems")
       source_requirements = { :default => default_source }
       @deps.each do |d|
         source_requirements[d.name] = d.source = default_source