cross test *bsd

[japaric]

Resources

• libc CI infrastructure
• how to build the *bsd toolchains. See build_*bsd_toolchain.sh.

Tentative next steps

• Create a minimal *BSD image that can run Rust programs and configure to run some predeterminated script at boot (libc does this).
  • Ideally, we want the image to be automagically created in this repo docker image
  • Alternatively, we can use @alexcrichton's images
• Update the Dockerifle to build and configure (env variables) the *bsd toolchains.
• Add logic to .travis.yml to test these targets.

By the way, @alexcrichton, do you have build instructions for the *bsd.qcow2 images libc uses in its tests? Also, is the "run this script at boot" logic hardcoded in image itself or can that be configured from the command line?

[alexcrichton]

I do indeed! Instructions are here with specific sections for FreeBSD and OpenBSD.

The general idea is to:

• Install a minimal system
• Configure startup to check for a disk being mounted
• If mounted, run a script and then shut down
• If not mounted, drop down to an interactive shell

Then to drive the tests you'd put everything you need into a disk image, spin qemu up with that image, and then scrape the output to see if the tests failed. This is all quite brittle, and isn't great b/c you basically have to pre-cache the built image (too slow or not scriptable to create), which reduces the utility over docker.