$ git clone -n https://src.fedoraproject.org/rpms/mozjs115.git /var/lib/mock/f41-build-side-1-2956605-35555/root/chroot_tmpdir/scmroot/mozjs115
Cloning into '/var/lib/mock/f41-build-side-1-2956605-35555/root/chroot_tmpdir/scmroot/mozjs115'...
$ git fetch origin defe281895f83829b6ef67d14844b58922e904f0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mozjs115
 * [new ref]         defe281895f83829b6ef67d14844b58922e904f0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at defe281 mozjs115-115.15.0 (RHBZ#2296304)