source $stdenv/setup set -x header "getting revision $selector"; done=; for source in $dbs; do if mtn pull --debug --db "$cacheDB" "$source" "${branch}"; then revision="$(mtn --db "$cacheDB" au toposort $(mtn --db "$cacheDB" au select "$selector") | tail -1)"; if [ -n "$revision" ]; then if mtn --db "$cacheDB" au get_revision "$revision"; then echo "found revision $revision" done=1; else echo "revision $revision does not exist"; fi else echo "selector $selector does not match any revision"; fi else echo "pulling branch $branch wasn't succesfull"; fi; if test -n "$done"; then break; fi; done; stopNest; header "checking out the revision $revision"; if test -n "$done"; then mtn checkout --db "$cacheDB" -r "$revision" "$out" -b "${branch}" else echo "Needed revision still not found. Exiting"; exit 1; fi; stopNest