[PATCH] Makefile: avoid non-standard sed expressions

[Mark Kettenis]

> Date: Wed, 27 Nov 2024 13:42:50 +0100
> From: Quentin Schulz <quentin.schulz at cherry.de>

Hi Quentin,

> Hi Mark,
> 
> On 11/26/24 8:12 PM, Mark Kettenis wrote:
> > The '?' that is used in the sed expression that determines MK_ARCH
> > is part of the extended regular expression syntax, but the default
> > behaviour of sed as specified by POSIX is to use only basic regular
> > expression syntax.  Use the equivalent '\{0,1\}' instead as
> > suggested by the OpenBSD re_format(7) man page.
> > 
> > Fixes: 04b1d84221d5 ("Makefile: fix empty MK_ARCH when using ccache")
> 
> Tested-by: Quentin Schulz <quentin.schulz at cherry.de>
> 
> Considering that it's not the first time someone breaks this by making 
> it non-POSIX, can you add a comment just above with a link to the 
> re_format(7) man page so people are at least more aware than they are 
> right now?

It is unfortunate that GNU sed has these extensions that are enabled
by default.  Just mentioning the OpenBSD man page is probably not
going to help, but I guess I could put in a link to

  https://man.openbsd.org/re_format

with a comment that only BREs should be used.

Cheers,

Mark

> 
> Thanks!
> Quentin
>