Install Scripts Shebang on Freebsd

[Sebastian Hugentobler]

The following files, used in the installation process, fail on FreeBSD (10.1):

• bootstrap.sh
• devtools/update_extlib.sh
• devtools/compile_translations.sh

Reason for this is the shebang line in all three:

#!/bin/bash

I replaced it with

#!/usr/bin/env sh

which works fine for me. Is there a specific reason for using bash here? If yes, could it be changed to use the env command? I can't symlink FreeBSDs default bash path (/usr/local/bin/bash) to /bin/bash from inside my jails as /bin is mounted readonly.

[Loic Dachary]

duplicate of #5315