bug#56030: The guix pull profile is too big

[(]

And considering the definition of system(3) in glibc:

@ sysdeps/posix/system.c (took me way too long to find this; glibc's
source code is a maze ;))
```
#define SHELL_PATH      "/bin/sh"       /* Path of the shell.  */
#define SHELL_NAME      "sh"            /* Name to give it.  */
```

couldn't we just use `-DSHELL_PATH=/gnu/store/...`?

    -- (