Hello,
"pelzflorian (Florian Pelz)" <pelzflor...@pelzflorian.de> writes:
> Wait wait Maxim, the discussion was that
> "B. Wilson" <elaexuo...@wilsonb.com> proposed
>> [PATCH] build: Let make use its hard-coded default shell
> > To: guix-patc...@gnu.org
>>
> > * configure.ac: Set AM_SUBST_NOTMAKE([SHELL])
> > +# Use make's hard-coded default shell. The make in a guix profile
> > +# defaults to the Right Thing, e.g. $GUIX_ENVIRONMENT/bin/sh
>> +AM_SUBST_NOTMAKE([SHELL])
>
> Then Maxim Cournoyer <maxim.courno...@gmail.com> writes:
>> This seems odd to me. Perhaps it'd be cleaner to detect which shell is
> > used at configure time to detect when /bin/sh != Bash, and warn that if
> > there are issues, the user should set the SHELL variable to Bash.
>
> elaexuo...@wilsonb.com writes:
>> Excellent. I agree it's probably not worth POSIXifying the scripts. Forcing
>> make to default to guix's bash seems like the right approach IMHO, so +1 for
>> that fix.
>
> I think we’re not on the same page. Is AM_SUBST_NOTMAKE([SHELL]) really
> problematic? Is seems like there is a legitimate use-case that foreign
> distro users with /bin/sh = dash would want “guix shell -D guix -- make”
> to just work without workaround? We could use elaexuotee’s
> AM_SUBST_NOTMAKE([SHELL]) patch, could we not?
Indeed, I had misunderstood, apologies. I've read the Autoconf/Automake
Info manuals about AM_SUBST and AM_SUBST_NOTMAKE, but I don't have a
clear understanding of the mechanisms involved.
from info '(autoconf) config.status Invocation':
-- Variable: CONFIG_SHELL
The shell with which to run ‘configure’. It must be
Bourne-compatible, and the absolute name of the shell should be
passed. The default is a shell that supports ‘LINENO’ if
available, and ‘/bin/sh’ otherwise.
So it appears to me that by default, it'd look for a shell that supports
LINENO if available, such as /bin/bash or something else? E.g., not use
the user's SHELL environment variable directly, but that can be
overridden with CONFIG_SHELL.
Using AC_SUBST_NOTMAKE([SHELL]) would cause SHELL to be substituted in
the build system files but prevent setting Make variables such as SHELL
= '/bin/...' in generated Makefiles... how do that end up causing the
Guix-provided Make to use its own "known" shell?
It seems to me that a potential pitfall would be that by adding
AC_SUBST_NOTMAKE([SHELL]), we'd change the default behavior of Autoconf,
which is to honor CONFIG_SHELL and set the SHELL Make variable based on
that; it seems it could be simpler to document that users on systems
using a Bourne incompatible shell should set CONFIG_SHELL to a Bourne
compatible one to build Guix from sources.
Is someone able to explain how the suggested fix work in more details?
Thanks,
Maxim
