"gem update" Fails, but "gem update X" works fine

[Randy Parker]

When I do a general "sudo gem update" on my mac, I get "could not find
gem X locally or in a repository".
But if I do "sudo gem update X", the gem gets updated without
incident.

This would be no big deal if "X" were the only gem suffering this
problem. However, the failure to update is happening to 100% of the
gems I have installed that can be updated. So far, I've had to
manually spell out the name of two dozen gems that "couldn't be found"
until I tried to update them by their specific name. All 24 of these
failures updated successfully when I spelled them out.

I posted my experience to my local Atlanta IRC channel. Three of the
four folks who tested "gem update" had the same problem. I first
noticed the problem on Tuesday, 6.30.2009. It continued to occur on
Weds and today.

sw_vers ==> Mac OS X 10.5.7

gem --version ==> 1.3.4

ruby --version ==> ruby 1.8.6 (2008-08-11 patchlevel 287) [universal-
darwin9.0]

gem sources ==> http://gems.rubyforge.org/ http://gems.github.com

The one guy for whom the entire set of installed gems updated cleanly
was also on a Mac running 10.5.7