Re: factor-parallel test failure with SHELL=zsh

[Jim Meyering]

On Thu, Jul 2, 2015 at 9:59 AM, Pádraig Brady <address@hidden> wrote:
> On 02/07/15 17:46, Jim Meyering wrote:
>> On Thu, Jul 2, 2015 at 4:57 AM, Pádraig Brady <address@hidden> wrote:
>>> On 02/07/15 08:08, Pádraig Brady wrote:
>>>> On 02/07/15 06:19, Jim Meyering wrote:
>>>>> For me, an obvious work-around is to set SHELL=/bin/sh
>>>>> or similar.
>>>>
>>>> Yes or to avoid the slight chance of /bin/sh also resetting the path
>>>> you could directly reference the binary as follows.
>>>> I slightly prefer setting the SHELL though.
>>>
>>> Yes given we should also set SHELL in tests/split/filter.sh,
>>> I'll apply the attached in your name later on.
>>
>> Thanks, but I would prefer to change init.sh to reject (or at least
>> deprioritize) zsh in that case. I'll propose a patch soon.
>
> Or I suppose any $SHELL so configured to reset the $PATH.
> I suppose we'd need the change to the tests also in case
> another shell was not found?

I realized that the problem was not that we were actually using
zsh, but that SHELL was set to /bin/zsh in spite of that script
being interpreted by /bin/sh. It appears that SHELL is set to
/bin/zsh at login, and no shell resets it.

This suggests a minimal change would be to add SHELL to
the list of envvars that we ensure are unset via
tests/envvar-check, and that does solve my problem.
However, I wonder if that is too large a sledgehammer.

An alternative would be to unset it only upon detecting this
misbehavior, e.g., adding these lines to that file:

diff --git a/tests/envvar-check b/tests/envvar-check
...
+# If invoking $SHELL -c 'CODE' puts a modified PATH in the environment,
+# as zsh does when ~/.zshenv modifies PATH, also unset SHELL.
+( PATH=$PATH:/no-such; $SHELL -c 'test '"$PATH"' = "$PATH"') \
+  || vars="$vars SHELL"
+
 for var in $vars

The disadvantage of that approach is that it imposes the cost
of a subshell and fork-exec of $SHELL prior to each and every test.

What do you think?

0001-tests-avoid-false-failure-of-factor-parallel.sh-with.patch
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