The 1.0.0.rc2 gem contents don't have a read permission, therefore the gem is unusable when it's installed system wide (with sudo), as users cannot read some files.
You'll probably want to check permissions and umask before packaging.
Just adding a note that the permissions problem for system-wide installations seems to have existed since 0.9.0, issue #176
I'm also having this issue with 1.0.0rc3.
# can't run 1.0.0rc3 as normal user
$ sudo gem install 'spork' --pre
/usr/local/bin/spork:19:in `load': no such file to load -- /usr/local/lib/ruby/gems/1.9/gems/spork-1.0.0rc3/bin/spork (LoadError)
from /usr/local/bin/spork:19:in `<main>'
$ ls -l /usr/local/lib/ruby/gems/1.9/gems/spork-1.0.0rc3/bin/spork
-rwx--x--x 1 root wheel 460 2012-08-12 15:32 /usr/local/lib/ruby/gems/1.9/gems/spork-1.0.0rc3/bin/spork
# works fine with 0.9
$ sudo gem install spork
$ ls -l /usr/local/lib/ruby/gems/1.9/gems/spork-0.9.2/bin/spork
-rwxr-xr-x 1 root wheel 460 2012-08-12 15:34 /usr/local/lib/ruby/gems/1.9/gems/spork-0.9.2/bin/spork
I'm also using spork '1.0.0rc3'. I was having problems until I changed the file permissions for the gem per romanbsd's comment (thank you).
What information would be appreciated to track down why it's installed as root when I bundle install? None of the other installed gems seem to have their permissions tweaked like that.