makerpms.sh executed by Bourne shell instead of bash

[philipp2100]

You're using #!/bin/sh here, though you use bash extensions like pushd. This should be #!/bin/bash.

https://github.com/sahlberg/libnfs/blob/030814506e529ef1f1572c7b6e3fc2e4c10cb544/packaging/RPM/makerpms.sh#L1