I had an almost similar problem as you where I had sqlite3 installed and yet the sqlite3 gem would not install. I was seeing an error message as follows, user-name-rajas-macbook-pro:rails3 user-namer$ gem install sqlite3 Building native extensions. This could take a while… ERROR: Error installing sqlite3: ERROR: Failed to build gem native extension. /Users/user-namer/.rvm/rubies/ruby-1.9.2-p180/bin/ruby extconf.rb … Read more
This is (what I would consider) a glitch with SQLite. This error occurs whether there are any records in the table or not. When adding a table from scratch, you can specify NOT NULL, which is what you’re doing with the “:null => false” notation. However, you can’t do this when adding a column. SQLite’s … Read more
You need the SQLite3 development headers for the gem’s native extension to compile against. You can install them by running (possibly with sudo): apt-get install libsqlite3-dev