Snagged from http://snippets.dzone.com/posts/show/5621 and posted here so I can find it later.

Installing a gem without the version works fine; installing a gem using “-v 2.x.x” or whatever version you like ends in:
spec_fetcher.rb:254: warning: getc is obsolete; use STDIN.getc instead

Guess what? RubyGems 1.3.7 doesn’t play nice with OSX 10.5.8. So downgrade to 1.3.6, or if you’re using RVM, do this:
echo 'rubygems_version=1.3.6' >> ~/.rvm/config/user ; rvm remove 1.8.7 ; rvm install 1.8.7

(assuming you are using 1.8.7 in your RVM, otherwise, use 1.9.1 or whatever)

Voila, works like a charm.

Thanks to Wayne E. Seguin for his help on irc.freenode.net #rvm (and for RVM in the first place!)

PS You may have to downgrade to 1.3.5 to get “rake gems:install” to work.

I did a website for recently an established webcomic and some of the old archive images were showing up in negative on some browsers, and not showing up at all in others. But it didn’t happen to all the images, and not on all browsers. I beat my head against this for a while.

When you can’t figure out what’s wrong with an image, you look at the image properties, rather than beat your head against a wall. This is what I suggest, anyway, because I didn’t do that.

They were CMYK.

CMYK images show as negative in Safari, and don’t show up at all in some versions of IE.

Yay. Great. Converted them to RGB, re-uploaded, all fixed.

“env: ruby: No such file or directory”

Maddening.

Turns out I didn’t have a environment.plist file in my /Users/(username)/.MacOSX/ directory, and even though it worked just fine before without it, that was no longer the case.

Here’s where to get a nifty little Ruby script to build it and even stick it in the right place for you. Note, the file must already exist, so you’ll have to make a .MacOSX directory in your user directory, and create an empty file “environment.plist.”

When using the autocomplete plugin that uses jQuery instead of scriptaculous, you need to add a route:

map.auto_complete ':controller/:action',
     :requirements => { :action => /auto_complete_for_\S+/ },
     :conditions => { :method => :get }

As per this post by the author of the plugin, who for some unknown reason hasn’t included that step with the instructions for the plugin. (WTF?) Otherwise it just sends the request to the show action, which looks at you stupidly and replies, “Couldn’t find FileData with ID=auto_complete_for_yourfieldname”, replacing “yourfieldname” with whatever you’d actually like it to return.