Portability issue on OSX: readlink
➜ citbx4gitlab git:(master) tools/ci-toolbox/ci-toolbox.sh setup
readlink: illegal option -- f
usage: readlink [-n] [file ...]
usage: dirname path
Related Stackoverflow question: https://stackoverflow.com/questions/1055671/how-can-i-get-the-behavior-of-gnus-readlink-f-on-a-mac
Not sure what the best way handling these kinds of incompatibility issues is.
(brew install coreutils
installs a compatible readlink in /usr/local/bin/greadlink
.)