This PR is easiest to review commit by commit.
Followup on https://github.com/bevyengine/bevy/pull/1309#issuecomment-767310084
- [x] Switch from a bash script to an xtask rust workspace member.
- Results in ~30s longer CI due to compilation of the xtask itself
- Enables Bevy contributors on any platform to run `cargo ci` to run linting -- if the default available Rust is the same version as on CI, then the command should give an identical result.
- [x] Use the xtask from official CI so there's only one place to update.
- [x] Bonus: Run clippy on the _entire_ workspace (existing CI setup was missing the `--workspace` flag
- [x] Clean up newly-exposed clippy errors
~#1388 builds on this to clean up newly discovered clippy errors -- I thought it might be nicer as a separate PR.~ Nope, merged it into this one so CI would pass.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
While generally speaking the calling thread would have picked up the task first anyways, I don't think it makes much sense usually to block the calling thread until another thread wakes and does the work.
* Switch from the deprecated `multitask` crate to `async-executor`
* async-executor appears to be essentially multitask 0.3
* use block_on in futures_lite instead of pollster because futures_lite is already in the dependency list of async-executor
