Ah I just remembered a few points, so I wanted to put some clarifications as well to make sure we’re all on the same page. Primarily, for each external dependency, I wouldn’t expect the rust to run tests, build documentation, or run document tests. Much of this is managed by these repos (through Cargo), and I don’t want to reencode all of Cargo’s logic into our own build system.
The second part I remembered is that the more dependencies we add on git submodules the more likely it is that over time you won’t be able to build old revisions of Rust. We try to be quite diligent with the rust-lang/llvm submodule by making sure that every branch always exists, but once we add a lot of upstream git dependencies there’s a high likelihood that historic git hashes disappear, git repos go away altogether, etc. Some possibilities to mitigate this are:
- We could download all crates from crates.io instead
- Mirrors could be made into the rust-lang organization specifically for hosting submodules of the rust repository
- We could stop development in-tree, but copy in the source from the external crate and add a stern warning that none of the files should be modified without just pulling in an upstream version.
I’m somewhat worried about this aspect, but not overly so as it would indeed be quite nice to start picking up some more flavorful projects outside of the compiler to make the compiler itself.
