$ git clone -n https://src.fedoraproject.org/rpms/webkit2gtk4.0.git /var/lib/mock/f40-build-2703082-70764/root/chroot_tmpdir/scmroot/webkit2gtk4.0
Cloning into '/var/lib/mock/f40-build-2703082-70764/root/chroot_tmpdir/scmroot/webkit2gtk4.0'...
$ git fetch origin dafff112f9d69ee9488f0a7ecf241a983cca17fd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/webkit2gtk4.0
 * [new ref]         dafff112f9d69ee9488f0a7ecf241a983cca17fd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dafff11 Update to WebKitGTK 2.42.5