Binary Code

Seems its possible to crash the current version of rcov hard under certain circumstances (version as of this writing: rcov (0.8.1.2.0)). If you find it crashing with:

ruby(17057,0xa0124720) malloc: *** error for object 0×5b1a602: Non-aligned pointer being freed
*** set a breakpoint in malloc_error_break to debug
/opt/local/lib/ruby/1.8/rss/rss.rb:274: [BUG] Segmentation fault
ruby 1.8.7 (2008-08-11 patchlevel 72) [i686-darwin9]
…
rake aborted!
NaN

Check to see if you have any empty helper files that don’t have any coverage. I had a couple that resembled the following. Removing them removed the “divide by zero” issue that causes the crash:

module ProductHelper
end

Update
Scratch that, it doesn’t entirely fix the issue. I’ve also implemented Stew Welbourne’s hack for round_to_tenths(decimal) in MetricFu but that too does not seem to be a complete solution. The seg fault still happens, though intermittently (sometimes it runs through the complete test suite, sometimes it doesn’t).

The search continues.

If you’re working in Rails and using date_select() or datetime_select() (and presumably select_date() and select_datetime()) and you find yourself up against an error like the following:

index 3873 out of string

Check that your :default parameter is either nil or an actual Date/Time/DateTime instance and not a String. Passing in a string as :default really messes things up.