$ git clone -n https://src.fedoraproject.org/rpms/plasma-welcome.git /var/lib/mock/f40-build-2526556-61812/root/chroot_tmpdir/scmroot/plasma-welcome
Cloning into '/var/lib/mock/f40-build-2526556-61812/root/chroot_tmpdir/scmroot/plasma-welcome'...
$ git fetch origin f75932627f1a92799bde46e3a616dda75afb3719:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-welcome
 * [new ref]         f75932627f1a92799bde46e3a616dda75afb3719 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f759326 6.0.1