Re: Autoconf. Generated configure file may use grep but does not unset the GREP_OPTIONS.

[Ralf Wildenhues]

* Eric Blake wrote on Thu, Apr 09, 2009 at 02:44:44AM CEST:
> According to Ralf Wildenhues on 4/8/2009 3:52 PM:
> >> Thanks for the report.  I agree that unsetting GREP_OPTIONS as part of
> >> AC_PROG_GREP (and friends) sounds reasonable,
> > 
> > Why not just unset it as part of AS_SHELL_SANITIZE?  There are lots of
> > plain grep uses in configure scripts.  I see this as sanitization
> > similar to LC_ALL.
> 
> Are there any other frequently-used *_OPTIONS variables that we should
> also consider unsetting?

We shouldn't unset anything that might be necessary for running the tool
successfully, such as M4PATH.  Hmm, may GREP_OPTIONS=--binary-files=...
be needed on w32 for some use cases within configure?

IIRC the bug report on mingw-users had an option in GREP_OPTIONS which
the grep did not even understand.  OTOH --color=always could easily
silently cause different (and wrong) behavior in configure.

Cheers,
Ralf