$ git clone -n https://src.fedoraproject.org/rpms/syncthing.git /var/lib/mock/f40-build-769156-125498/root/chroot_tmpdir/scmroot/syncthing
Cloning into '/var/lib/mock/f40-build-769156-125498/root/chroot_tmpdir/scmroot/syncthing'...
$ git fetch origin 54b34c21fdbac0131b6b373a965ed73d5c558dc7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/syncthing
 * [new ref]         54b34c21fdbac0131b6b373a965ed73d5c558dc7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 54b34c2 Update to version 1.27.1; Fixes RHBZ#2252714