$ git clone -n https://src.fedoraproject.org/rpms/openh264.git /var/lib/mock/f40-build-787970-134983/root/chroot_tmpdir/scmroot/openh264
Cloning into '/var/lib/mock/f40-build-787970-134983/root/chroot_tmpdir/scmroot/openh264'...
$ git fetch origin 67d9f025778cd60259b7c51de98f23d1416eb853:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openh264
 * [new ref]         67d9f025778cd60259b7c51de98f23d1416eb853 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 67d9f02 Drop the gstreamer plugin as it's part of Fedora proper now