From: Eric Hodel <drbrain@...7.net>
Date: 2009-05-21T04:11:27+09:00
Subject: Re: undefined method `empty?' for nil:NilClass in gem build

On May 20, 2009, at 10:08, Ken Bloom wrote:

> I'm trying to build a rubygem, but I keep getting the following error.
> Can anybody help?
>
> $ gem build wordnet.gemspec
> ERROR:  While executing gem ... (NoMethodError)
>    undefined method `empty?' for nil:NilClass
>
> $ cat wordnet.gemspec
> Gem::Specification.new do |s|
>  s.name="WordNet"
>  s.author="Ken Bloom"
>  s.email="kbloom@gmail.com"
>  s.version="1.0.1"
>  s.summary="A binding to the WordNet C library"
>  s.require_path="ext"
>
>  #disabled because it spews lots of errors
>  #but the generated rdoc isn't useful in the least
>  s.has_rdoc=false

Note that RDoc 1.3.3 ignores this setting and always generates RDoc.

DON'T be lazy, document your code!  (You may want to install RDoc 2 if  
you're getting warnings)

>  s.files += Dir["ext/*"]
>  s.extensions << "ext/extconf.rb"
> end
>
> $ gem environment
> RubyGems Environment:
>  - RUBYGEMS VERSION: 1.3.2

Maybe there's a bug in 1.3.2, try upgrading:

$ touch ext/extconf.rb

NOTE: DON'T be lazy, do it right!  You forgot to specify all these  
things.  Filling them in is in the best interests of everyone.

$ gem build wordnet.gemspec
WARNING:  no description specified
WARNING:  no homepage specified
WARNING:  no rubyforge_project specified
   Successfully built RubyGem
   Name: WordNet
   Version: 1.0.1
   File: WordNet-1.0.1.gem
$ gem env version
1.3.3