Non-portable configure.ac

[Jan-Marek Glogowski]

Am 22.02.2018 um 18:36 schrieb Sander Maijers:
> Note that checkbashisms 2.17.12-1 failed to catch this when I debugged
> this issue.
> 
> https://www.archlinux.org/packages/community/any/checkbashisms/
> 
> Also note that on Arch Linux, I used dash 0.5.9.1-1, whereas Debian only
> has various older versions
> 
> https://packages.debian.org/search?keywords=dash
> 
> Running shellcheck and checkbashisms regularly is advisable even for
> autoconf generated scripts.

On my Ubuntu I also have sh -> dash. But I guess, like most people, I
use autogen.sh to run configure with flags from autogen.input.

And autogen.sh is really a Perl script, and Perls system call runs
configure by calling "bash ./configure …". That's probably why nobody
caught this yet. Now I have no idea why Perls system function uses bash
as shell…

Jan-Marek