Tried to run go test.

On what?

(github.com/Thomasdezeeuw/markdown seems to be private)

If your tests take a long time to run, then "go test" is going to take a long time run. That is definitely the first thing to investigate.

If you are absolutely certain that the problem is not in your code, then you need to give us a test case we can use to replicate the problem ourselves. Otherwise there is nothing we can do.

The code is indeed private at the moment, however normally the tests run fine in under two seconds. But even if the code is problem isn't there a timeout option normally?

Running go test timeout 2s, it correctly timeouts. Could it be that 1.4 had a default timeout and 1.5 doesn't?

Both Go 1.4 and 1.5 have a default timeout of 10 minutes. However, I don't how that could be the issue here. You seem to be suggesting that your tests complete quickly with Go 1.4 but sometimes hang with Go 1.5. Look at http://tip.golang.org/doc/go1.5#runtime . Is it possible that your tests or code are depending on a specific goroutine scheduling order?

You could also try to run the test with the race detector on

go test -race

I'm going to close this, running with a timeout is good enough for me.

In case anyone wonders why 'go test' takes forever (>10s) on a Windows machine with Avast, you might want to disable Avast's DeepScreen, it tries to sandbox the code and analyze your binary.

It took my way too long to figure this out. More details here.