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

[Ilay Bobir]

Ralf Wildenhues wrote:
> * 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?

If you need an option in GREP_OPTIONS for you code to run correctly you 
should add the option yourself.  If you are unsure make a test.

The main problem is that currently you can not rely on the fact that on 
the target machine grep will be executed with the default options if you 
do not specify any.


> [...] 
> OTOH --color=always could easily
> silently cause different (and wrong) behavior in configure.

--line-number breaks libtool that is for sure.