Perfecting Rust Packaging

[brson]

@cuviper

Please count me among the Fedora interested parties. For reference, here's the packaging bug, but there hasn't been much activity lately.

Will do! You are on my contact list.

@cuviper

I'll try to give a fuller reply later, but one thing I don't see mentioned at all here is ABI. Fedora usually avoids static linking in packages, but I don't see how we can ship any dylibs if there's no way to update them. Even just std is questionable, it seems.

Yes, this is the case. Using dylibs for the most common thing dylibs are used for (providing ABI-compatible updates) is not viable in Rust right now. Static linking is strongly preferred by the entire system atm. Solving this is far-future territory

Since Rust much prefers static linking, will Fedora use it, or will Fedora want to dylib crates anyway?

We may be able to make some quick fixes here on native dylibs. I suspect that a lot of crates are 'vendoring' their native libs and not providing an option to dynamically link them. Not sure. cc @alexcrichton.

@cuviper

I think Fedora would even be fine rolling along with 6-week rust updates, IF we could do it without rebuilding every other rust-built package each time, not to mention whatever the users built themselves.

Ouch... I don't think there will be any hope of this any time soon. Presently in Rust, when anything upstream changes, including the compiler, all downstream must be rebuilt.

@mneumann

@brson: Would be nice to ping the FreeBSD port maintainer too (you can find him here).

Done. Thanks. I can't believe I completely excluded BSD. I've also pinged @dhuseby

@mneumann

rustc statically links in LLVM libraries. When LLVM is installed system-wide, this is maybe not the right choice. In case of FreeBSD, beginning with LLVM 3.7, they stopped building static libraries. So it's no longer possible to use the system-wide LLVM anymore and one has to use the LLVM shipped with Rust, which costs a lot of build time (~1 hour for LLVM, 30 min for rustc). Optional dynamic linking to the rescue?

Yes, I think we this is or will be an option. There's a PR open now trying to improve support. I was not aware that 3.7 didn't support static linking. Wonder what we're doing in-tree...