[Debian-med-packaging] Bug#861281: rnahybrid: FTBFS on armel

[Lennart Sorensen]

On Tue, Sep 26, 2017 at 08:19:59PM +0100, Edmund Grimley Evans wrote:
> It's a possibility to bear in mind, definitely, but the
> perhaps-infinite loop can be observed with a cross-compiler:
> 
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=876825

I just tried doing the cross compile manually, and it does actually
complete, but it takes MUCH longer than the native x86 compile.  So at
least with gcc 7.2.0 it is NOT an infinite loop, it just looks like it.

On this machine it takes about 50 seconds to compile energy.c for amd64,
and it takes the cross compiler 25 minutes to compile energy.c for armel.
It also used 660MB ram, while the amd64 compile only used 150MB.
Maybe the extra registers on arm is making the compiler try a lot more
optimization possibilities with all the loops.

So I can see how the armel build machine is timing out.  Also it means
gcc does NOT have an infinite loop bug, at least not in 7.2.  I suspect
gcc 6 didn't either.

> (I will test with the compilers in unstable, as requested, if no one
> else gets there first.)

Well I tried as you can see.

> I don't think the buildds report memory usage, but the time is 150 minutes:
> 
> https://buildd.debian.org/status/logs.php?pkg=rnahybrid&arch=armel

So the build timeout is too short for this package on that build machine
with the way gcc optimizes now.

-- 
Len Sorensen