Handle bad gem_dir from gemspec object

lib/solargraph/gem_pins.rb

@@ -46,6 +46,7 @@ def self.combine_method_pins(*pins)
     # @return [Array<Pin::Base>]
     def self.build_yard_pins(yard_plugins, gemspec)
       Yardoc.cache(yard_plugins, gemspec) unless Yardoc.cached?(gemspec)
+      return [] unless Yardoc.cached?(gemspec)
       yardoc = Yardoc.load!(gemspec)
       YardMap::Mapper.new(yardoc, gemspec).map
     end

lib/solargraph/yardoc.rb

@@ -18,6 +18,15 @@ def cache(yard_plugins, gemspec)
       path = PinCache.yardoc_path gemspec
       return path if cached?(gemspec)
 
+      unless Dir.exist? gemspec.gem_dir
+        # Can happen in at least some (old?) RubyGems versions when we
+        # have a gemspec describing a standard library like bundler.
+        #
+        # https://github.com/apiology/solargraph/actions/runs/17650140201/job/50158676842?pr=10
+        Solargraph.logger.info { "Bad info from gemspec - #{gemspec.gem_dir} does not exist" }
+        return path
+      end
+
       Solargraph.logger.info "Caching yardoc for #{gemspec.name} #{gemspec.version}"
       cmd = "yardoc --db #{path} --no-output --plugin solargraph"
       yard_plugins.each { |plugin| cmd << " --plugin #{plugin}" }

spec/gem_pins_spec.rb

@@ -11,4 +11,9 @@
     expect(core_root.return_type.to_s).to eq('Pathname, nil')
     expect(core_root.location.filename).to end_with('environment_loader.rb')
   end
+
+  it 'does not error out when handed incorrect gemspec' do
+    gemspec = instance_double(Gem::Specification, name: 'foo', version: '1.0', gem_dir: '/not-there')
+    expect { Solargraph::GemPins.build_yard_pins([], gemspec) }.not_to raise_error
+  end
 end