Re: [PATCH] test-lib: don't use ulimit in test prerequisites on cygwin

[Michael J Gruber <git@grubix.eu>]

Jonathan Nieder venit, vidit, dixit 13.09.2017 21:20:
> Ramsay Jones wrote:
> 
>> On cygwin (and MinGW), the 'ulimit' built-in bash command does not have
>> the desired effect of limiting the resources of new processes, at least
>> for the stack and file descriptors. However, it always returns success
>> and leads to several test prerequisites being erroneously set to true.
>>
>> Add a check for cygwin and MinGW to the prerequisite expressions, using
>> 'uname -s', and return false instead of (indirectly) using 'ulimit'.
>> This affects the prerequisite expressions for the ULIMIT_STACK_SIZE,
>> CMDLINE_LIMIT and ULIMIT_FILE_DESCRIPTORS prerequisites.
>>
>> Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
>> ---
>>  t/t1400-update-ref.sh | 11 ++++++++++-
>>  t/t6120-describe.sh   |  1 -
>>  t/t7004-tag.sh        |  1 -
>>  t/test-lib.sh         | 22 ++++++++++++++++++++--
>>  4 files changed, 30 insertions(+), 5 deletions(-)
> 
> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
> 
> Thanks.
> 
> An alternative would be to do some more explicit feature-based test
> like using "ulimit" to set a limit and then reading back the limit in
> a separate process, but that feels like overkill.

It's still not clear whether these limits would be in effect or just
reported.

Rather than checking uname -s in several places, I think we should just
define ulimit to be false in one place, or rather set the prerequisite
there.

Michael