Merge remote-tracking branch 'origin/shell-bisector'

membench-bisect

@@ -0,0 +1,42 @@
+#!/bin/sh
+
+set -xeu
+
+precision=${1:-25000}
+start_fail=${2:-6000000}
+start_pass=${3:-16000000}
+
+iteration=0
+while true
+do if test -f 'membench-last-fail.json'
+   then last_fail=$(jq '.memLimit' 'membench-last-fail.json')
+   else last_fail=$start_fail; fi
+
+   if test -f 'membench-last-pass.json'
+   then last_pass=$(jq '.memLimit' 'membench-last-pass.json')
+   else last_pass=$start_pass; fi
+
+   outcome_gap=$(($last_pass - $last_fail))
+   echo "membench:  pass/fail outcome gap: $outcome_gap"
+   if test $outcome_gap -le $precision
+   then echo "membench:  outcome gap below precision $precision, terminating"; exit 0
+   else echo "membench:  outcome gap above precision $precision, next iteration"; fi
+
+   nextLimit=$((($last_fail + $last_pass) / 2))
+
+   echo "{ memLimit: $nextLimit }" > 'membench-limit.json'
+   time nix build '.#membench' -L --out-link 'membench-last'
+   # nix-store -r $(readlink ./result) --add-root 'membench-last' --indirect
+
+   lastResult=$(jq .failed 'result/refined.json')
+   if [ x$lastResult = xfalse ]
+   then outcome=pass
+   else outcome=fail; fi
+
+   cp -f 'membench-last/refined.json' 'membench-last-'$outcome'.json'
+   rm -f 'membench-last-'$outcome; mv 'membench-last' 'membench-last-'$outcome
+
+   echo "--------------------------------- iteration $iteration boundaries:"
+   jq . 'membench-last-fail.json'
+   jq . 'membench-last-pass.json'
+done