Support cross compiling

[expipiplus1]

I guess this would involve using rustc.nativeDrv instead of rustc and changing some of the info passed to cargo. I'm no rust expert and wasn't able to get this working in a few minutes of trying.

[nmattia]

Hey @expipiplus1 , can you clarify what you mean by "cross compiling"? I've meant to add wasm and musl builds to naersk, just haven't found the time yet. I'll also need to write a guide on how I do it at $WORK. Do you mean more cross compilation targets?

[giodamelio]

Just running into this now. Wanting to do a x86_64-unknown-linux-musl build to be deployed to AWS Lambda. I will tinker with this a bit the next few days, but I am a total Nix beginner.

[nmattia]

Let me get started on this, I have the code lying around, just need to integrate it. First I want to extend the test suite to run on multiple nixpkgs versions, otherwise it's going to be hell to debug.

[nmattia]

#88

[giodamelio]

Thanks so much! I gave it a shot, but it was a little much for my novice Nix skills.

If you need any help testing let me know, I can at least be a beta tester.

[nmattia]

Thanks! I've created a bunch of tickets: https://github.com/nmattia/naersk/issues?q=+is%3Aissue+label%3Amusl+

Last night I added a definition for rustc with a wasm32 and a musl target (#90). The next step is to actually provide a way of using it (#93). After that, you can knock yourself out :)

[angerman]

hooray, I've just bumped into this as well. Looking at #98, and specifically at

https://github.com/nmattia/naersk/pull/98/files#diff-6938ea327f87ba609b4fafc30775f3e9R38-R39

I'm left to believe that cross compilation should be as easy as setting a different
CARGO_BUILD_TARGET? How does that inherit the toolchain? And what about rust libraries that link against system libraries and would expect those to be cross compiled as well?

[cpick]

There's now an example for building against musl.

[expipiplus1]

Thank you! If only I could remember what I initially needed this for!