testing: an import cycle in a test file exposes an infinite loop in the go test command or the go cover tool #9031

by mdwhatcott:

What does 'go version' print?

go version go1.3.3 darwin/amd64

What steps reproduce the problem?

1. go get github.com/mdwhatcott/cycle
2. cd $GOPATH/src/github.com/mdwhatcott/cycle
3. go test -cover

What happened? The go test command hangs indefinitely.

What should have happened instead? It should report a build failure due to an import
cycle.

Please provide any additional information below.

See the README.md file in the "github.com/mdwhatcott/cycle" package for more
details.

I understand that coverage information is only useful when the tests successfully
compile and execute, but in every other failure to compile, the command in step 3 above
reports the problem and exits with a non-zero return status. Why should an import cycle
not cause the same behavior?