Steven Walter
29b5f6eadd
Rust's symbol hashes break sstate, because a subsequent build of the same input hash may generate different symbol hashes. This means that packages that previously built against the "same" (from bitbake's perspective) rustc would no longer run, and bitbake would not know to rebuild them because the input hash is the same. This is because the crate metadata contains some data that differs from build-to-build. This problem actually extends beyond the compiler to any arbitrary crate, for the same reason. If a crate in the middle of the dependency chain had to be rebuilt, bitbake wouldn't realized that all its dependencies have to be relink, and the dependent packages would fail due to missing symbols. Fortunately, bitbake's input hash makes this mechanism largely unnecessary; any change to rust's source or configuration will cause rustc and all dependencies to rebuild. Therefore, it's safe to remove crate metadata from the hashing.
Introduction
This openembedded layer provides the rust compiler, tools for building packages (cargo), and a few example projects.
What works:
- MACHINE="beaglebone" (TARGET_SYS=arm-poky-linux-gnueabi)
- Building rust-native, rust-cross, rust-hello-world, cargo-native
- Running/using all of these (including rust-hello-world)
What doesn't:
- Probably some of the untested things
What's untested:
- rust (built for target)
- Other TARGETs
Common issues when packaging things using cargo
You may run into errors similar to:
| src/lib.rs:12:1: 12:35 error: can't find crate for `ffi`
| src/lib.rs:12 extern crate "openssl-sys" as ffi;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Where a "-sys" crate (or other crate) is not found. These are typically caused
by a crate's Cargo.toml including triplet-specific dependencies and then using
the crate based on a feature (most often, #[cfg(unix)]). Until cargo and it's
ecosystem get their act together, you'll need to supply patches to the
misbehaving packages. See recipies/cargo/cargo_*.bb for an example of how to
do this.
TODO
- -crosssdk and -buildsdk packages
- -runtime? (install target libraries on target)
- Upstream local rustc patches for libdir and bindir support
- add bitbake fetch support for crates.io
- add required cargo package registry clones in SRC_URI to prevent the need for network when building.
Pitfalls
- TARGET_SYS must be different from BUILD_SYS. This is due to the way configuration options are tracked for different targets.
Dependencies
On the host: unknown
On the target: unknown
Maintainer(s) & Patch policy
Open a Pull Request
Copyright
MIT/Apache-2.0 - Same as rust