--- /dev/null
+#!/bin/bash
+
+# the revision that we noticed does not longer build
+LATEST_BAD_REV=$1
+
+# an older revision that is known to build
+LAST_KNOWN_GOOD_REV=$2
+
+# count the number of commits
+COUNT=`mtn log --brief --no-merges --no-graph --to p:$LAST_KNOWN_GOOD_REV --from $LATEST_BAD_REV | tee /tmp/candidates.txt | wc -l`
+
+echo $COUNT commits
+
+# if COUNT == 1 stop
+
+# make binary sections
+COUNT=$(($(($COUNT + 1)) / 2))
+
+CANDIDATE_REV=`cat /tmp/candidates.txt | head -n $COUNT | tail -n 1 | sed -e 's@\([a-f0-9]*\) .*@\1@'`
+
+echo $CANDIDATE_REV
+
+echo mtn up -r $CANDIDATE_REV
+mtn up -r $CANDIDATE_REV
+
+