[bug#28660] [PATCH] gnu: python-numpy: Give sh store location instead of setting $SHELL.

[Thomas Danckaert <post@thomasdanckaert.be>]

From: Christopher Baines <mail@cbaines.net>
Subject: Re: [bug#28660] [PATCH] gnu: python-numpy: Give sh store 
location instead of setting $SHELL.
Date: Wed, 4 Oct 2017 07:30:48 +0100

> Could bash be specified as an input, and that used instead? This 
> would
> mean that the behaviour of the package is more isolated from the
> environment.

Sounds good, but I'm afraid I don't understand what you mean (maybe 
it's still too early in the morning).  If we add a "bash" to the 
package inputs, it will still come from the store.  So probably you 
mean something else by “specified as an input”?

> For example, on non GuixSD systems, /bin/sh could be something other
> than bash. But, if the numpy package depends on some bash in the 
> store,
> and uses that, then it would be isolated from this.

That's true, though users on such systems could set $SHELL to 
override the default one from the store.  But maybe avoiding having 
to do that is what you mean by “more isolated from the environment”?

The shell is used for very limited purposes anyway (essentially to 
run C and Fortran compilers to build extenstions, AFAIU), but I'm 
happy to improve the patch if it's useful.  If you have a solution 
that allows users to use their own /bin/sh if they want, but still 
works for all builds of dependent packages on Guix, please explain :-)

Thomas