undefined method `except' for "":String

Environment:

Ruby 1.9.2 via rvm, Running phusion passenger with apache and nginx (had to setup virtual host as proxy to get this to run multiple versions of ruby), Rails 3.0.8, Datamapper via the dm-rails gem. Mac OS X.

Error Message:

undefined method `except' for "":String

Problem:
For me this was in my database.yml file. Don't really know what the issue was, but I'm guessing an extra space or tab some where in the defaults section of the database.yml file.

Fix:
All I did was delete the defaults section and of course added the adapter, username, password, host, etc to each corresponding section in the database.yml file.

initialize: not in gzip format (Zlib::GzipFile::Error

Error message:

/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/site_ruby/1.8/rubygems/package/tar_input.rb:49:in `initialize': not in gzip format (Zlib::GzipFile::Error
 

Problem:

Github may go down/timeout during deploy

Fix:

1. ssh into the server

2. cd to your current deploy folder

3. run bundle show 'name of gem' (shows the location of the gem install)

4. cd to the /gems/ path that is shown in the previous step

5.  run ls -l to see the latest install of the gem

6. run rm -rf on that directory (the latest gem install)

You have already activated rack 1.1.1, but your Gemfile requires rack 1.1.2. Consider using bundle exec.

Error message:

You have already activated rack 1.1.1, but your Gemfile requires rack 1.1.2. Consider using bundle exec.

Problem:
Passenger preloads gems from global gem list if you have passenger spawn method set. My problem is two fold, i was using passenger spawn method and i didn't have version 1.1.2 of rack installed globally.

Fix:

Remove the passenger spawn method from httpd.conf and restart apache