$ go test ./...
----------------------------------------------------------------------
FAIL: functions_test.go:68: functionSuite.TestDeferredAnnotatef
functions_test.go:81:
c.Assert(errors.Details(err), jc.Contains, tagToLocation["deferredAnnotate"].String())
... obtained string = "[{github.com/juju/errors/functions_test.go:76: deferred annotate} {github.com/juju/errors/functions_test.go:73: first}]"
... expected string = "github.com/juju/errors/functions_test.go:77"
OOPS: 20 passed, 1 FAILED
--- FAIL: Test (0.01s)
FAIL
FAIL github.com/juju/errors 0.016s