[qubes-users] slock issue

Hi guys,
I recently tried to switch from i3lock to slock, but when I run 'sudo ./slock' (it needs suid/sgid) I get this error:
slock: crypt: Invalid argument
I installed libxcrypt-compat, which slock needed.
It's supposed to be compatible with libcrypt(not found).
journalctl -f only shows successes while running the command.
I tried to remove i3lock in case of conflict, but i3-settings-qubes depends on it.
I tried to compile slock without any patches, same error when running that.
I managed to get it to run with the PAM_auth patch, which replaces the use of shadow, but I couldn't unlock slock with my password, so that doesn't really help me.
Is there a trick to it or does it simply not work on Qubes/Fedora?
Thanks in advance for any replies.