TestKeepWorkDir fails on Windows

[rillig]

To reproduce:

cmd /c ver

Microsoft Windows [Version 10.0.17134.228]

git co 788fd78401277ebd861206a03c884797c6ec5541

go test

Output:

FAIL: run_test.go:409: RunS.TestKeepWorkDir

run_test.go:414:
    c.Assert(result.String(), Matches, ".*\nWORK="+result.WorkDir)
... value string = "" +
...     "OK: 1 passed\n" +
...     "WORK=C:\\Users\\rillig\\Program Files\\cygwin\\tmp\\check-8674665223082153551"
... regex string = "" +
...     ".*\n" +
...     "WORK=C:\\Users\\rillig\\Program Files\\cygwin\\tmp\\check-8674665223082153551"
... Can't compile regex: error parsing regexp: invalid escape sequence: `\U`

Either result.WorkDir should be properly escaped, or the temporary directory should be replaced with a placeholder before the comparison. I did the latter variant in pkglint, search for func (t *Tester) Output() string.

[jhenstridge]

This looks to be fixed by 10cb982 (which updates the CI to run the test suite on Windows), which quotes WorkDir using regexp.QuoteMeta to make it safe to include in the regular expression.