| # Prerequisites |
| |
| ## Dependencies |
| |
| See [the `rust-lang/rust` INSTALL](https://github.com/rust-lang/rust/blob/master/INSTALL.md#dependencies). |
| |
| ## Hardware |
| |
| You will need an internet connection to build. The bootstrapping process |
| involves updating git submodules and downloading a beta compiler. It doesn't |
| need to be super fast, but that can help. |
| |
| There are no strict hardware requirements, but building the compiler is |
| computationally expensive, so a beefier machine will help, and I wouldn't |
| recommend trying to build on a Raspberry Pi! We recommend the following. |
| * 30GB+ of free disk space. Otherwise, you will have to keep |
| clearing incremental caches. More space is better, the compiler is a bit of a |
| hog; it's a problem we are aware of. |
| * 8GB+ RAM |
| * 2+ cores. Having more cores really helps. 10 or 20 or more is not too many! |
| |
| Beefier machines will lead to much faster builds. If your machine is not very |
| powerful, a common strategy is to only use `./x check` on your local machine |
| and let the CI build test your changes when you push to a PR branch. |
| |
| Building the compiler takes more than half an hour on my moderately powerful |
| laptop. We suggest downloading LLVM from CI so you don't have to build it from source |
| ([see here][config]). |
| |
| Like `cargo`, the build system will use as many cores as possible. Sometimes |
| this can cause you to run low on memory. You can use `-j` to adjust the number |
| of concurrent jobs. If a full build takes more than ~45 minutes to an hour, you |
| are probably spending most of the time swapping memory in and out; try using |
| `-j1`. |
| |
| If you don't have too much free disk space, you may want to turn off |
| incremental compilation ([see here][config]). This will make compilation take |
| longer (especially after a rebase), but will save a ton of space from the |
| incremental caches. |
| |
| [config]: ./how-to-build-and-run.md#create-a-bootstraptoml |
