Link statically against musl libc

[tailhook]

Currently we kinda rely on unsupported and buggy feature of linking against glibc. Should instead link against musl libc

Some info: https://gist.github.com/cl91/bb927df2525738502131#file-static-linking-against-musl-md

[bstrie]

This is now supported in the nightly version of the Rust compiler, on an experimental basis:

rust-lang/rust#24777

[aidanhs]

I'm curious - why do you say this is buggy?

[tailhook]

I'm curious - why do you say this is buggy?

1. Some functions are two order of magnitude slower (e.g. clock_gettime)
2. glibc still tries to use *.so plugins even if statically built. When they are absent on system (e.g. in container), it's ok (except some function don't work). But on host system when .so plugins files are not ABI-compatible with glibc compiled into vagga, it just crashes with segmentation fault.

To name a few, just from the top of my head.

[aidanhs]

Gotcha, was aware of these, just wanted to check there are no others. Thanks :)

[tailhook]

It's done in master. Will do some testing before the release though.