Bug#819278: llvm-toolchain-3.8: Build not reliable

[Santiago Vila]

tags 819278 help
thanks

I would welcome any help to reproduce this.

Some theories about why this might fail:


* Lack of memory. Thanks to a cron job looking at /proc/meminfo, I know
that llvm-toolchain-3.8 needs at least 4600 M of memory to build. Last
two times I tried I had only 3500 M and 8000 M of swap.

If this were the case, I would expect an "Out of memory" error,
but not a hang.


* Using only 1 CPU. My virtual machines have only one CPU most of the
time. Since I collect measurements of the time required to build
packages, I tell sbuild to define parallel=1 in DEB_BUILD_OPTIONS,
so that all measurements are on the same scale.

In the past, I found at least one case where a package built fine with
2 CPU and FTBFS with only 1 CPU. It happened to be a bug in the
Makefiles.


* I build with "dpkg-buildpackage -A". It could still be that the test
suite expects some program to be there which was not created in the
build-indep target and hangs as a result.


* Some bug in sbuild which nobody reported yet. I'm using sbuild 0.68
from jessie-backports because version 0.69 has a bug that makes the
required disk space figures to be very wrong.


Thanks.