I'm new to Jruby and was working through building a "Hello World" out of the box using the latest Rails.

On build:

jruby 1.6.7.2 (ruby-1.9.2-p312) (2012-05-01 26e08ba) (Java HotSpot(TM) 64-Bit Server VM 1.7.0_09) [darwin-x86_64-java]

The rake assets:precompile command consistently fails with:

stat.st_gid unsupported or native support failed to load
org/jruby/RubyFileStat.java:432:in gid' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/activesupport-3.2.3/lib/active_support/core_ext/file/atomic.rb:39:inatomic_write'
/Users/frank/.rvm/gems/jruby-1.6.7.2/gems/activesupport-3.2.3/lib/active_support/cache/file_store.rb:91:in write_entry' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/activesupport-3.2.3/lib/active_support/cache/strategy/local_cache.rb:140:inwrite_entry'
/Users/frank/.rvm/gems/jruby-1.6.7.2/gems/activesupport-3.2.3/lib/active_support/cache.rb:364:in write' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/activesupport-3.2.3/lib/active_support/cache.rb:520:ininstrument'
/Users/frank/.rvm/gems/jruby-1.6.7.2/gems/activesupport-3.2.3/lib/active_support/cache.rb:362:in write' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/caching.rb:90:incache_set'
/Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/caching.rb:53:in cache_set_hash' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/caching.rb:24:incache_asset'
/Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/index.rb:88:in build_asset' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/base.rb:163:infind_asset'
/Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/index.rb:56:in find_asset' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/actionpack-3.2.3/lib/sprockets/static_compiler.rb:20:incompile'
/Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/base.rb:212:in each_logical_path' /Users/frank/.rvm/gems/jruby-1.6.7.2/gems/sprockets-2.1.3/lib/sprockets/base.rb:200:ineach_file'

...

I have posted more details in the GIST at https://gist.github.com/3924671.

I have confirmed that this error happens in both Java 1.6 and 1.7 on Mac OS X. I was not able to reproduce the error on Ubuntu Linux, wherein the command worked as expected.

As this is my first attempt at building a "Hello World" Rails application in JRuby, I do not have much more to provide at this time in terms of troubleshooting the route cause.