# re_build_tools
Part of the [`rerun`](https://github.com/rerun-io/rerun) family of crates.
[](https://crates.io/crates/re_build_tools)
[](https://docs.rs/re_build_tools)


Library to be used in `build.rs` files in order to build the build info defined in `re_build_info` by setting environment variables.
Some information in `re_build_info` can be provided through env vars:
- `GIT_HASH` (the full sha, like `e264b9decab9257ae79100a006bb69c0d289e20c`)
- `GIT_BRANCH` (the `symbolic-ref --short`, like `asdf/my-branch`)
- `DATETIME` (ISO8601, like `2025-12-10T15:49:52.089915278Z`)
If these are required but not provided, they will be gathered by:
- `GIT_HASH`: running `git rev-parse HEAD`
- `GIT_BRANCH`: running `git symbolic-ref --short HEAD`
- `DATETIME` retrieving system time during the build
If you'd like to avoid these for whatever reason, then set them externally.