Re: What 'sh' should 'system' use?

[Philip McGrath <philip@philipmcgrath.com>]

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On Sunday, October 16, 2022 3:04:45 AM EDT Liliana Marie Prikler wrote:
> Am Samstag, dem 15.10.2022 um 19:23 -0400 schrieb Philip McGrath:
> > On Saturday, October 1, 2022 12:54:27 PM EDT Ludovic Courtès wrote:
> > > Hello!
> > > 
> > > Philip McGrath <philip@philipmcgrath.com> skribis:
> > > > 1) If we want to continue to hard-code a specific shell into
> > > > Glibc, I
> > > > think we should document the decision (for example, why 'bash-
> > > > static' vs.
> > > > 'bash- minimal'?) […]
> > > 
> > > The choice of ‘bash-static’ rather than ‘bash-minimal’ is motivated
> > > by
> > > the fact that, in (gnu packages commencement), we want to make sure
> > > ‘glibc-final’ does not retain references to its build-time
> > > environment.
> > > See #:allowed-references in ‘glibc-final’.
> > 
> > This makes sense as far as using 'bash-static' in Glibc. The aspects
> > I'm unsure of are:
> > 
> >  1. If I'm packaging software that implements a function like
> > 
> >     'system' (e.g. Racket, SML/NJ, Chez Scheme, etc.), should I use
> >     'bash-minimal' or 'bash-static'?
> > 
> >  2. Do we really need 'bash-minimal' at all? Why not just replace it
> > 
> >     with 'bash-static'?
> 
> We already explained those two to you. Racket, SML/NJ, Chez Scheme et
> al. are not bootstrap-relevant, thus they can use bash-minimal.  Unlike
> bash-static, bash-minimal can be grafted, i.e. a security bug in bash(-
> minimal) that necessitates a version bump or similar does not cause a
> world rebuild.  A security bug in bash-static does.
> 

I don't think I understand this. Does it mean that, in the following, I am 
running a Bash that wouldn't have security bugs fixed? If so, that seems quite 
bad!

--8<---------------cut here---------------start------------->8---
philip@bastet:/tmp$ cat run-bshell.scm 
(use-modules
 (guix build-system gnu)
 (guix gexp)
 ((guix licenses) #:prefix license:)
 (guix packages))
(define src
  (plain-file "run-bshell.c"
              "
#include <stdlib.h>
#include <unistd.h>
#include <paths.h>
int main(void)
{
  execl(_PATH_BSHELL,
        _PATH_BSHELL,
        \"-c\",
        \"echo \" _PATH_BSHELL,
        (char *)NULL);
}
"))
(package
  (name "run-bshell")
  (version "0")
  (source src)
  (build-system gnu-build-system)
  (arguments
   (list
    #:phases
    #~(modify-phases %standard-phases
        (delete 'configure)
        (replace 'build
          (lambda args
            (invoke "gcc" "-o" "run-bshell" #$src)))
        (delete 'check)
        (replace 'install
          (lambda args
            (install-file "run-bshell" (string-append #$output "/bin")))))))
  (home-page #f)
  (synopsis #f)
  (description #f)
  (license license:cc0))
philip@bastet:/tmp$ guix shell --rebuild-cache --container --no-cwd -f run-
bshell.scm -- run-bshell
substitute: updating substitutes from 'https://bordeaux-us-east-mirror.cbaines.nsubstitute: updating substitutes from 'https://bordeaux-us-east-mirror.cbaines.net'... 100.0%
substitute: updating substitutes from 'https://bordeaux.guix.gnu.org'... 
100.0%
substitute: updating substitutes from 'https://ci.guix.gnu.org'... 100.0%
The following derivations will be built:
  /gnu/store/q5bib9dgaxzag29a2l4b833mm5l12dx3-profile.drv
  /gnu/store/r45khn1mq17fc0xsab1yszii85ynsm2j-run-bshell-0.drv

building /gnu/store/r45khn1mq17fc0xsab1yszii85ynsm2j-run-bshell-0.drv...
building CA certificate bundle...
listing Emacs sub-directories...
building fonts directory...
building directory of Info manuals...
building profile with 1 package...
/gnu/store/720rj90bch716isd8z7lcwrnvz28ap4y-bash-static-5.1.8/bin/sh
philip@bastet:/tmp$ 
--8<---------------cut here---------------end--------------->8---

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