The terseness of the output comes from an impedance mismatch between the error handling in main.go (which invokes log.Fatal liberally, as if invoked as a binary) and the testing strategy in doc_test.go (which invokes do as though it expects that function to return explicit errors instead of terminating the process).
This test was fixed by changing cmd/doc behavior in CL 204442.
Backporting that non-test code change is unlikely to be appropriate
this late in Go 1.13 release cycle. A failing test can cover up other
regressions, so skip this known failing test to fix the builder.
Run-TryBot: Dmitri Shuralyov <email@example.com>
Reviewed-by: Alexander Rakoczy <firstname.lastname@example.org>
Reviewed-by: Carlos Amedee <email@example.com>