hexmake

Hexmake runs a multi-step build using caching. You give it a file describing all the possible build steps along with their inputs and outputs. The tool will then chain them together to produce an output, use cached results from prior builds when possible.

The tool does not handle other steps of a build and is designed to fit into the build ecosystem you already have. You are in the sweet spot for this tool if either of these is true:

• You started out using shell scripts for running builds and tests, but your project has become complicated enough that builds take multiple steps and run slowly. You would like to stop building the world all the time and switch to only rebuilding things when their inputs have changed.
• You have implemented Bazel, Pants, or Buck, but you are finding that you regularly spend an hour or more fighting the tool to get it to do something you want. Hexmake is less opinionated and more general-purpose than these tools and is a fit whenever you would prefer to write a little script code of your own rather than file tickets with a plugin author.

Hexmake is inspired by Make and comes with some newer features:

• Process whole directory trees as inputs, not just individual files.
• Support .gitignore files so that builds will only depend on checked-in source code.
• When deciding whether to rebuild, use the contents of the files rather than their timestamps.
• Also treat a change in command line or a change in environment variables as grounds for rebuilding.
• Consistently put all build outputs into an out directory rather than back into the source tree.
• Run builds in a separate sandbox directory. That way, if you depend on an input you did not declare, it will usually cause a build break.

Hexmake leaves some things out on purpose:

• It provides no way to build and host major development tools such as Firefox or Docker. You are expected to install those separately.
• It has no built-in variables or control structures. Instead, you should wrap Hexmake with a script in your own preferred scripting language such as Python, Ruby, or Node.