$ git clone -n https://src.fedoraproject.org/rpms/postbooks.git /var/lib/mock/f31-build-49350-27272/root/chroot_tmpdir/scmroot/postbooks
Cloning into '/var/lib/mock/f31-build-49350-27272/root/chroot_tmpdir/scmroot/postbooks'...
$ git reset --hard 3a993918624d4d88b53be7abdffdeede48d9bf9c
HEAD is now at 3a99391 rebuild (qt5)