Resolving problems
If your build fails, it may be because of a build.rs: programs which do arbitrary
things at build time. This is fundamentally at odds with the design of gn
and ninja which aim for static, deterministic, build rules to maximize
parallelism and repeatability of builds.
Some build.rs actions are automatically supported; others require action:
| build script effect | Supported by our gn templates | Work required by you |
|---|---|---|
| Checking rustc version to configure features on and off | Yes | None |
| Checking platform or CPU to configure features on and off | Yes | None |
| Generating code | Yes | Yes - specify in gnrt_config.toml |
| Building C/C++ | No | Patch around it |
| Arbitrary other actions | No | Patch around it |
Fortunately, most crates don’t contain a build script, and fortunately, most build scripts only do the top two actions.