Re: factor-parallel test failure with SHELL=zsh

[Pádraig Brady]

On 03/07/15 01:26, Jim Meyering wrote:
> 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.

Another possible disadvantage is that $SHELL might induce other
undetected issues other than $PATH, like resetting environment variables
removed in tests/envvar-check etc.

Since $SHELL isn't reset by the non interactive shells in the tests,
and it's used implicitly in various places in the tests, how about
we set it consistently for all test sub scripts.  How about the attached
which sets it to the value determined by the gnulib posix-shell module?

cheers,
Pádraig.

coreutils-SHELL.patch
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