From: Eric Wong <normalperson@...>
Date: 2014-12-31T00:10:38+00:00
Subject: [ruby-core:67239] Re: [ruby-trunk - Bug #10681] Segfault on Debian Jessie Linux

louis@lpil.uk wrote:
> I've just installed `ruby 2.1.0p0 (2013-12-25 revision 44422)
> [x86_64-linux]` and the same thing happens. I tried it on my other
> computer, also Debian Jessie, and it ran happily without segfault.

I guess this is a bug triggered in alsa-rawmidi due to different
hardware configurations.

> -- Control frame information -----------------------------------------------
> c:0021 p:---- s:0082 e:000081 CFUNC  :snd_ctl_rawmidi_next_device
> c:0020 p:0038 s:0077 e:000076 BLOCK  /home/louis/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/alsa-rawmidi-0.3.1/lib/alsa-rawmidi/api.rb:407 [FINISH]
> c:0019 p:---- s:0073 e:000072 CFUNC  :select
> c:0018 p:0027 s:0070 e:000069 METHOD /home/louis/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/alsa-rawmidi-0.3.1/lib/alsa-rawmidi/api.rb:405

I would try editing alsa-rawmidi/api.rb and printing out the values
of `handle', `device_id', and `n' in that loop before the crashing line.

I suggest contacting the alsa-rawmidi author for more help.