If you are using /bin/sh you need to check sure it is a POSIX shell script and not using bash features [1]. On Debian and derivatives /bin/sh is ash not bash.

If you are using /bin/sh you need to check sure it is a POSIX shell script and not using bash features [1]. On Debian and derivatives /bin/sh is ash not bash. [1] https://linux.die.net/man/1/checkbashisms https://linux.die.net/man/1/checkbashisms