ansaurus

Question

Why is Ruby throwing a Segmentation fault on only my system, and only in this Rails application?

Answer 1

A:

It sounds like these are hardware errors rather than software errors. Get your machine checked out, especially the memory.

Mick Sharpe 2010-01-21 20:20:38

Thanks for the response Mick. I could be mistaken here, but if it were a problem with physical memory wouldn't it be more inconsistent or intermittent? Wouldn't I also experience even worse crashes in other environments? Wouldn't restarting the machine likely make it go away for awhile?As it stands, the error occurs every single time I execute this particular line of code in this particular environment, even after multiple restarts - but not in any other application.

Luke Bayes 2010-01-21 21:03:50

Answer 2

A:

Sounds like you have the wrong gem version, or it's incompatible with MacOS. From the RDoc:

Users of Linux, Unix, BSD, etc., will want the unix package. Ara’s Open4 gem is a dependency. Users of the Ruby One-Click Installer (OCI) will want to select the gem appropriate their version of Ruby. The real issue here is compiler version. The wrong version will SEGFAULT due to some incompatibility somewhere in the VC++ compiler or libraries

klochner 2010-01-21 21:45:07

It turns out, I'm not using the POpen4 gem (it's not installed either), I am using Ara Howard's Open4 gem and calling popen4 on that. Based on your response, I tried uninstalling and reinstalling the open4 gem which did upgrade the version number I had installed (from 0.9.6 to 1.0.1). Alas - still crashing.

Luke Bayes 2010-01-21 22:10:35

Does the gem work with other commands (besides swfmill)?

klochner 2010-01-21 23:02:32

Yes, the Open.popen4 code works great with other executables and it _even_ works with swfmill when run outside of this Rails application. Even with the exact same values being sent to it.I'm starting to suspect some dynamically linked library interacting across loaded/activated gems?

Luke Bayes 2010-01-21 23:28:23

What do you get with /usr/local/bin/ruby -v

klochner 2010-01-22 00:05:33

ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.2.0]

Luke Bayes 2010-01-22 07:40:57

My next move would be to make sure the gem is ok with your 64 bit processor. c extensions can run into trouble if they're compiled for the wrong architecture. I suggest you check out the project page and contact the gem author - http://rubyforge.org/projects/codeforpeople/ sorry i couldn't be of more help, but this is a nasty one

klochner 2010-01-22 16:31:13

Answer 3

+1 A:

I don't have a solution, but I've identified a way to reproduce this issue.

After installing the ruby-debug-0.10.3 gem today, my Rails 2.1.1 test that calls 'stderr.read' within an

Open4::popen4( "FOO" ) do | pid, stdin, stdout, stderr |
    stderr.read
end

block has started throwing same '[BUG] Bus Error ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.2.0]' that you're getting.

If I 'sudo gem uninstall ruby-debug', the test runs and passes. If I then 'sudo gem install ruby-debug' again, the test throws.

I'm running a Rails 2.1.1 project on Snow Leopard with Ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.2.0] installed.

Rebuilding the ruby-debug gem for 64-bit isn't fixing the issue for me.

alimills 2010-02-16 22:41:43

I get exactly the same behavior on my system.

Luke Bayes 2010-02-17 07:54:06

Answer 4

+2 A:

I just ran into a similar issue myself.

It's typically caused by a gem with natively compiled bits that's loading a library compiled for a different architecture. (Sounds like you've been down that path already.)

Unfortunately, this also includes libraries that are compiled as universal binaries.

In my case the problem was caused because Ruby was loading the wrong version of OpenSSL. Perhaps the problem is similar for you. Based on the answers above it sounds like ruby-debug is causing the problem. Could it be linking against the wrong library?

Here are some links about the problem that helped me:

Luke Francl 2010-02-18 05:56:18

Thanks Luke - it turns out it was caused by recent releases of ruby-debug. I filed a bug with that project and for now the workaround is to install an older version...

Luke Bayes 2010-02-23 18:29:56

Answer 5

+3 A:

Ok, I've fixed this on my machine. I'm not sure exactly why, but downgrading the ruby-debug gem to version 0.10.0 solves the problem for me.

The specific fix is running the following commands:

sudo gem uninstall ruby-debug

sudo gem install ruby-debug --version 0.10.0

alimills 2010-02-23 18:24:59

Luke Bayes 2010-02-23 18:28:52

ansaurus

tags:

views:

answers:

Why is Ruby throwing a Segmentation fault on only my system, and only in this Rails application?

related questions