e2ab98df08
None of the tools seem to need syn 0.15.35, so we can just build syn 1.0. This was causing an issue with clippy's `compile-test` program: since multiple versions of `syn` would exist in the build directory, we would non-deterministically pick one based on filesystem iteration order. If the pre-1.0 version of `syn` was picked, a strange build error would occur (see https://github.com/rust-lang/rust/pull/73594#issuecomment-647671463) To prevent this kind of issue from happening again, we now panic if we find multiple versions of a crate in the build directly, instead of silently picking the first version we find. |
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| .. | ||
| Cargo.toml | ||
| lib.rs | ||
| README.md | ||
rustc-workspace-hack
This crate is a bit of a hack to make workspaces in rustc work a bit better.
The rationale for this existence is a bit subtle, but the general idea is that
we want commands like ./x.py build src/tools/{rls,clippy,cargo} to share as
many dependencies as possible.
Each invocation is a different invocation of Cargo, however. Each time Cargo runs a build it will re-resolve the dependency graph, notably selecting different features sometimes for each build.
For example, let's say there's a very deep dependency like num-traits in each
of these builds. For Cargo the num-traits's default feature is turned off.
In RLS, however, the default feature is turned. This means that building Cargo
and then the RLS will actually build Cargo twice (as a transitive dependency
changed). This is bad!
The goal of this crate is to solve this problem and ensure that the resolved dependency graph for all of these tools is the same in the various subsets of each tool, notably enabling the same features of transitive dependencies.
All tools vendored here depend on the rustc-workspace-hack crate on crates.io.
When on crates.io this crate is an empty crate that is just a noop. We override
it, however, in this workspace to this crate here, which means we can control
crates in the dependency graph for each of these tools.