bisect

A program for bisection of integer ranges

Description

bisect is a program for bisecting integer ranges. It takes a known good index and a bad index and finds the first bad index, e.g. the commit that introduced a bug or the optimization pass which causes a miscompile. Both positive (good < bad) and negative (bad < good) ranges are supported.

bisect either works with a command to distinguish good or bad outcomes, or in interactive mode.

Examples

A simple example, script.sh returns 0 on good outcomes and non-0 on bad ones.

bisect 0 10 bash script.sh {}

Use -- for negative values, otherwise the positional argument is interpreted as an option.

bisect -- 123 -10 check.sh {}

git bisect (but I haven't had a chance to test this for real)

bisect 5 0 -- sh -c 'git checkout main~{} && dune test'

If the command is omitted, bisect in interactive mode

bisect 0 10