$ git clone -n https://src.fedoraproject.org/rpms/gnome-shell-extensions.git /var/lib/mock/f41-build-1285100-23248/root/chroot_tmpdir/scmroot/gnome-shell-extensions
Cloning into '/var/lib/mock/f41-build-1285100-23248/root/chroot_tmpdir/scmroot/gnome-shell-extensions'...
$ git fetch origin 15751a9f8fcfbcd3afca779eed2a053ede3513dc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-shell-extensions
 * [new ref]         15751a9f8fcfbcd3afca779eed2a053ede3513dc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 15751a9 Conditionalize Xorg session