Re: [PATCH] t0213: skip ancestry tests under user-mode emulation

Junio C Hamano <[email protected]> writes:

> "Jamie Magee via GitGitGadget" <[email protected]> writes:
>
>> -# Determine if cmd_ancestry is supported on this platform.
>> +# Enable these tests only when cmd_ancestry reports real process names.
>> +# The procinfo stub emits no event; under user-mode emulation (e.g.
>> +# qemu-user) /proc reports the emulator, not the guest. Spawn test-tool
>> +# from test-tool and require "test-tool" in the child's ancestry.
>
> T.r.i.c.k.y. ;-)
>
>>  test_expect_success 'detect cmd_ancestry support' '
>>  	test_when_finished "rm -f trace.detect" &&
>>  	GIT_TRACE2_BRIEF=1 GIT_TRACE2="$(pwd)/trace.detect" \
>> -		test-tool trace2 001return 0 &&
>> -	if grep -q "^cmd_ancestry" trace.detect
>> +		test-tool trace2 004child test-tool trace2 001return 0 &&
>> +	if grep -q "^cmd_ancestry.*test-tool" trace.detect
>
> This will be happy even if "test-tool-trash" that happens to have
> "test-tool" as its prefix appears on a cmd_ancestry line (for that
> matter, things like "cmd_ancestry-not-quite" that has "cmd_ancestry"
> as its prefix would be accepted).  I guess that is OK because we are
> testing this in a fairly tightly controlled environment (trace keys
> are taken from known vocabulary, not arbitrary strings, for example).
>
> Will queue.  Thanks.

Just to clarify, 'Will queue' simply means that the patch will
appear in 'seen'.  It does not imply that I have personally
reviewed the change and found it acceptable to merge into 'next'.

I would appreciate a review from someone familiar with the trace2
facility.

Thanks.