Re: Bug#830353: ruby-kgio: FTBFS: ERROR: Test "ruby2.3" failed.

[Eric Wong <e@80x24.org>]

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?

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*)

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.

----8<----
Subject: [PATCH] test: increase random blob size for giant socket buffers

Socket buffers on some systems may be too big to trigger
partial write/blocking behavior we need for our tests.
Increase it to 20M for now and see if we can fix an FTBFS
on larger machines: https://bugs.debian.org/830353

This should also speed up tests a little since urandom is
slow and reading 10M from it in the first place was lazy.
---
 test/lib_read_write.rb | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/test/lib_read_write.rb b/test/lib_read_write.rb
index 26e7aef..f5c5bf8 100644
--- a/test/lib_read_write.rb
+++ b/test/lib_read_write.rb
@@ -7,7 +7,12 @@ $-w = true
 require 'kgio'
 
 module LibReadWriteTest
-  RANDOM_BLOB = File.open("/dev/urandom") { |fp| fp.read(10 * 1024 * 1024) }
+  RANDOM_BLOB = File.open("/dev/urandom") do |fp|
+    nr = 31
+    buf = fp.read(nr)
+    # get roughly a 20MB block of random data
+    (buf * (20 * 1024 * 1024 / nr)) + (buf * rand(123))
+  end
 
   def teardown
     @rd.close if defined?(@rd) && ! @rd.closed?
-- 
EW