have a buildbot that test compile for multiple targets

[semarie]

Having a buildbot that try to compile multiple targets could help for detect commits that would break targets without dedicated buildbots (in mind it is openbsd target, but it could apply to others, like dragonfly for example).

The purpose isn't to run a fully test suite (it isn't possible for all targets without a dedicated buildbot) but only ensure that the compilation don't break. It would at least be better than today, where you can break something without known.

It would help commiters to ensure that their PR don't break too badly uncommon targets.

[semarie]

I currently take a look at reducing the toolchain needed when cross-building some libraries.
It should be possible to build several libs without any cross-linking, by forcing building rlib instead of dylib crates.

Using this method, under openbsd I am able to build TARGET_CRATES of dragonfly (libc, std, flate, arena, term, serialize, getopts, collections, test, rand, log, graphviz, core, rbml, alloc, unicode, and rustc_bitflags), by passing RUSTFLAGS_{crate}=--crate-type rlib at make invocation.

[steveklabnik]

Triage: I don't believe that this is something that's been done, and I'm not sure it's something that there's plans to do.

[alexcrichton]

Given that we now have bots cross-compiling to FreeBSD and NetBSD, I think this is done :)