$ git clone -n https://src.fedoraproject.org/rpms/gnome-tweaks.git /var/lib/mock/f40-build-2218200-52595/root/chroot_tmpdir/scmroot/gnome-tweaks
Cloning into '/var/lib/mock/f40-build-2218200-52595/root/chroot_tmpdir/scmroot/gnome-tweaks'...
$ git fetch origin f605dcecd4f064ad637271e1dca2e9f89692e6d4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-tweaks
 * [new ref]         f605dcecd4f064ad637271e1dca2e9f89692e6d4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f605dce Update to 45.0