Improve error message when no buildable cgo sources are found (#687)
Improve error message when no buildable cgo sources are found (#687)


bazelbuild/rules_go,Xjs/rules_go,bazelbuild/rules_go,Xjs/rules_go,Xjs/rules_go,Xjs/rules_go,bazelbuild/rules_go,bazelbuild/rules_go,Xjs/rules_go,bazelbuild/rules_go