[Pkg-rust-maintainers] Bug#822325: rustc: FTBFS in testing: test fail

[Luca BRUNO]

severity 822325 minor
tags 822325 + moreinfo
thanks

On Sat, 23 Apr 2016 14:33:48 +0200 (CEST) Santiago Vila <sanvila at unex.es> 
wrote:

> This package currently fails to build from source in stretch.
> 
> ------------------------------------------
> executing x86_64-unknown-linux-gnu/test/run-pass/tcp-stress.stage2-x86_64-
> unknown-linux-gnu 
> ------stdout------------------------------
> 
> ------stderr------------------------------
> thread '<main>' panicked at 'called `Result::unwrap()` on an `Err` value: 
> RecvError', src/libcore/result.rs:746
> 
> ------------------------------------------
> 
> The build was made on two different QEMU virtual machines with 4GB RAM
> and 4GB swap, running stretch, using sbuild.

This looks like an artifact due to your build environment, as I just tried 
building on a physical stretch amd64 machine and all tests pass:
"""
summary of 50 test runs: 10108 passed; 0 failed; 88 ignored; 0 measured 
"""

A couple of ideas regarding this test:
 * it is heavily threaded, it may trigger some data races in qemu
 * it may be slow to run and thus timing out. Can you try increasing the
   timeout at the top of src/test/run-pass/tcp-stress.rs?
 * It may be dropping the sender to early. Can you try moving the `drop(tx)`
   just before `process::exit(0)`?

Anyway, this looks like just some test instability on an emulated environment, 
and not a real regression. Thus I'm downgrading it.

Can you please try the small changes I suggested above? If so, it may be worth
reporting it directly to upstream.

Ciao, Luca