Rust: Compilation of other backends

[eliasboegel]

Hi,

I'm currently trying out a basic Rust example. libCEED was added as a dependency as per the docs:

[dependencies]
libceed = "0.12.0"

I am using only QFrunctions from the gallery. The standard /cpu/self/ref/*, /cpu/self/opt/* backends run fine, however any other backend gives the error:

Backend not currently compiled: <backend>
Consult the installation instructions to compile this backend

I see that the (C) build section in the docs does state that some additional flags must be specified to compile with support for a given backend. Is there currently a way to let the Rust bindings compile libceed with additional flags/backends?

[jedbrown]

Hi, thanks for the question. We haven't added cuda/hip/sycl features to the libceed-sys package, but you can build libceed.so any way you like and then use the system feature to use that pre-built library instead of having libceed-sys/build.rs build its own. We'd be happy to accept a pull request that added such features, though they may be somewhat brittle because one needs build.rs to find the toolchain (CUDA) that the user intends.

[eliasboegel]

Thanks!