bug#25954: cargo-build-flags pushed to master as 49744b352371a875f685ddd0fd1e0c5e7eb10e70

[Danny Milosavljevic]

Hi ng0,

my notes contain this:

       ;; (crate-uri "libc" version) doesn't contain libc-test.
       (uri (string-append "https://github.com/rust-lang/libc/archive/"; version 
".tar.gz"))
.

So please try this one.

Also, actually running the tests would be using rust-ctest which would cause a 
reference cycle:

  rust-ctest - rust-gcc - rust-tempdir - rust-rand - rust-libc; note: also 
because of rust-rayon as well.

I'm trying to fix that by replacing rust-tempdir by a rust-tempdir that 
generates non-random tempdirs.
I've removed rayon completely.

rust-ctest also depends on rust-syntex-syntax which is also a problem.  
Therefore, I tried to make it depend on a very old syntax-syntax (0.3) instead 
- which is much simpler (has fewer parts).  But that one doesn't compile using 
newer Rust - so I've started adapting it.  Sigh.

In general Rust is very very bad at reproducible bootstrapping - as can be seen 
here.

I think as a first step we should just disable libc tests for now - the amount 
of changes required is really too high.  That should be done upstream instead.