Use lld for rustdoc on Linux in config_fast_builds.toml (#14839)

# Objective

Running `cargo ci` on Fedora 40 causes a system crash due to many `ld`
processes consuming all available memory when performing doc tests.

## Solution

This PR extends #13553.

- Add reference to #12207 in the CI sections of `CONTRIBUTING.md` and
`config_fast_builds.toml`.
- Add sample `rustdocflags` configurations for `lld` and `mold` to
`config_fast_builds.toml` for Linux.

## Testing

Crashing configuration

- config.toml
  ```
  [target.x86_64-unknown-linux-gnu]
  linker = "clang"
  rustflags = ["-Clink-arg=-fuse-ld=lld"]
  
  [alias]
  ci = "run --package ci --"
  ```
- Test command
  `cargo ci`

Working configuration

- config.toml
  ```
  [target.x86_64-unknown-linux-gnu]
  linker = "clang"
  rustflags = ["-Clink-arg=-fuse-ld=lld"]
  rustdocflags = ["-Clink-arg=-fuse-ld=lld"]
  
  [alias]
  ci = "run --package ci --"
  ```
- Test command
  `cargo ci`
This commit is contained in:
Christian Robles 2024-08-22 16:08:04 -07:00 committed by GitHub
parent f9fbd08f9f
commit 35fb54fa49
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2 changed files with 11 additions and 2 deletions

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@ -83,12 +83,21 @@ rustflags = [
# - Ubuntu: `sudo apt-get install mold clang`
# - Fedora: `sudo dnf install mold clang`
# - Arch: `sudo pacman -S mold clang`
# "-Clink-arg=-fuse-ld=/usr/bin/mold",
# "-Clink-arg=-fuse-ld=mold",
# Nightly
# "-Zshare-generics=y",
# "-Zthreads=0",
]
# Some systems may experience linker performance issues when running doc tests.
# See https://github.com/bevyengine/bevy/issues/12207 for details.
rustdocflags = [
# LLD linker
"-Clink-arg=-fuse-ld=lld",
# Mold linker
# "-Clink-arg=-fuse-ld=mold",
]
[target.x86_64-apple-darwin]
rustflags = [

View file

@ -423,7 +423,7 @@ If you're new to Bevy, here's the workflow we use:
2. Make your changes in a local clone of your fork, typically in its own new branch.
1. Try to split your work into separate commits, each with a distinct purpose. Be particularly mindful of this when responding to reviews so it's easy to see what's changed.
2. Tip: [You can set up a global `.gitignore` file](https://docs.github.com/en/get-started/getting-started-with-git/ignoring-files#configuring-ignored-files-for-all-repositories-on-your-computer) to exclude your operating system/text editor's special/temporary files. (e.g. `.DS_Store`, `thumbs.db`, `*~`, `*.swp` or `*.swo`) This allows us to keep the `.gitignore` file in the repo uncluttered.
3. To test CI validations locally, run the `cargo run -p ci` command. This will run most checks that happen in CI, but can take some time. You can also run sub-commands to iterate faster depending on what you're contributing:
3. To test CI validations locally, run the `cargo run -p ci` command. This will run most checks that happen in CI, but can take some time. Some systems may experience [linker performance issues when running doc tests](https://github.com/bevyengine/bevy/issues/12207). You can also run sub-commands to iterate faster depending on what you're contributing:
* `cargo run -p ci -- lints` - to run formatting and clippy.
* `cargo run -p ci -- test` - to run tests.
* `cargo run -p ci -- doc` - to run doc tests and doc checks.