Default branch in git repositories != master
A fresh clone of a repository will check out a default branch != master, most likely the first one in alphabetical order. See the example:
pcbe13089:~$ git clone ssh://git@ohwr.org:7999/project/fmc-tdc-sw.git
Cloning into 'fmc-tdc-sw'...
remote: Enumerating objects: 3178, done.
[...]
Resolving deltas: 100% (2223/2223), done.
pcbe13089:~$ cd fmc-tdc-sw/
pcbe13089:fmc-tdc-sw$ ls
COPYING doc drivers lib Makefile README test
pcbe13089:fmc-tdc-sw$ git branch
* backport-tdc-v1.0
pcbe13089:fmc-tdc-sw$ git branch -a
* backport-tdc-v1.0
remotes/origin/HEAD -> origin/backport-tdc-v1.0
remotes/origin/backport-tdc-v1.0
[...]
remotes/origin/master
[...]
Reported by @FedericoVaga