<pre class="notranslate">This looks pretty new. Haven't seen this particular failure before.

What steps will reproduce the problem?

run net/http tests in a loop

What do you see instead?

=== RUN TestServeFileMimeType-65
--- FAIL: TestServeFileMimeType-65 (0.00 seconds)
fs_test.go:338:     Content-Type mismatch: got "text/plain; charset=utf-8", want
"text/css; charset=utf-8"

Which compiler are you using (5g, 6g, 8g, gccgo)?

6g

Which operating system are you using?

linux

Which version are you using?  (run 'go version')

8afe25accb81</pre>
<p dir="auto">GOTRACEBACK controls what gets printed on failure. By default "a failure prints a stack trace for every extant goroutine, eliding functions internal to the run-time system, and then exits with exit code 2."</p>
<p dir="auto">It would be nice if we there was a variant that printed just the offending goroutine, which is usually what you care about during development.</p>