Control: retitle -1 ruby-kgio: FTBFS on Amazon EC2: ERROR: Test "ruby2.3" failed.
Control: severity -1 important

On Fri, Jul 08, 2016 at 06:53:29PM +0000, Eric Wong wrote:
> Lucas Nussbaum <lucas@debian.org> wrote:
> > The full build log is available from:
> >    http://people.debian.org/~lucas/logs/2016/07/07/ruby-kgio_2.10.0-1_unstable_reb.normal.log
> > 
> > A list of current common problems and possible solutions is available at
> > http://wiki.debian.org/qa.debian.org/FTBFS . You're welcome to contribute!
> > 
> > About the archive rebuild: The rebuild was done on EC2 VM instances from
> > Amazon Web Services, using a clean, minimal and up-to-date chroot. Every
> > failed build was retried once to eliminate random failures.
> 
> Thanks for the report.  Can you try the patch below?

Didn't help.

I can't, however, reproduce this locally on my workstation.

I remember hitting this type of issue with kgio whenever I did rebuilds of all
Ruby packages on an Amazon EC2 instance, and then couldn't reproduce it
locally.

If you want to give a closer look I can give you access to the VM I use for
these builds, where I can consistently reproduce this.

> I'd be interested to know what non-standard sysctl knobs are set
> for kernel socket buffer sizes (in /proc/sys/net/{core,ipv4}/*mem*)

$ tail -n 1000 /proc/sys/net/{core,ipv4}/*mem*
==> /proc/sys/net/core/optmem_max <==
20480

==> /proc/sys/net/core/rmem_default <==
212992

==> /proc/sys/net/core/rmem_max <==
16777216

==> /proc/sys/net/core/wmem_default <==
212992

==> /proc/sys/net/core/wmem_max <==
16777216

==> /proc/sys/net/ipv4/igmp_max_memberships <==
20

==> /proc/sys/net/ipv4/tcp_mem <==
2954019 3938693 5908038

==> /proc/sys/net/ipv4/tcp_rmem <==
4096    12582912        16777216

==> /proc/sys/net/ipv4/tcp_wmem <==
4096    12582912        16777216

==> /proc/sys/net/ipv4/udp_mem <==
2954019 3938693 5908038

==> /proc/sys/net/ipv4/udp_rmem_min <==
4096

==> /proc/sys/net/ipv4/udp_wmem_min <==
4096

> You can also increase the 20M to 30M or whatever (otoh, that
> means using more memory during tests :<)
> 
> I'm not comfortable calling setsockopt to set SO_{SND,RCV}BUF
> knobs since that can trigger VM deadlock bugs on some older
> kernels, too.
> 
> Anyways, most of the kgio functionality is in Ruby 2.3 nowadays
> and kgio can probably go away when support for 2.2 can be
> dropped in gems.

In Debian we don't even have 2.2 anymore. The only things using kgio are
unicorn and rainbows. Maybe if their dependency on kgio could be skipped on
Ruby 2.3, we could drop kgio from Debian.