rake install fails but gem install works fine - ruby

Question

bundle exec rake install fails, but gem install works. How to solve the problem?
I found a similar problem and he solved the problem by adding puts out in install gem method. I did same, but the error message just indicate somewhere nil.to_s is called.
rake install fails but gem install works fine, any idea why?
Error Message
be rake install --trace
** Invoke install (first_time)
** Invoke build (first_time)
** Execute build
gnf 0.1.2 built to pkg/gnf-0.1.2.gem.
** Execute install
ERROR: While executing gem ... (TypeError)
no implicit conversion of nil into String
rake aborted!
Couldn't install gem, run `gem install /Users/ironsand/dev/gnf/pkg/gnf-0.1.2.gem' for more detailed output
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.10.3/lib/bundler/gem_helper.rb:88:in `install_gem'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.10.3/lib/bundler/gem_helper.rb:44:in `block in install'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/task.rb:240:in `call'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/task.rb:240:in `block in execute'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/task.rb:235:in `each'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/task.rb:235:in `execute'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/task.rb:179:in `block in invoke_with_call_chain'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/task.rb:172:in `invoke_with_call_chain'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/task.rb:165:in `invoke'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:150:in `invoke_task'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:106:in `block (2 levels) in top_level'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:106:in `each'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:106:in `block in top_level'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:115:in `run_with_threads'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:100:in `top_level'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:78:in `block in run'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:176:in `standard_exception_handling'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/application.rb:75:in `run'
/Users/ironsand/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/rake-10.4.2/bin/rake:33:in `<top (required)>'
/Users/ironsand/.rbenv/versions/2.2.2/bin/rake:23:in `load'
/Users/ironsand/.rbenv/versions/2.2.2/bin/rake:23:in `<main>'
Tasks: TOP => install
gem install
There is no error with the command:
gem install /Users/ironsand/dev/gnf/pkg/gnf-0.1.2.gem
gnf.gemspec
coding: utf-8
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'gnf/version'
Gem::Specification.new do |spec|
spec.name = 'gnf'
spec.version = GNF::VERSION
spec.authors = ['ironsand']
spec.email = ['ironsand#example.com']
spec.licenses = ['MIT']
spec.summary = %q{GFN}
spec.description = %q{GFN}
spec.homepage = 'http://github.com/ironsand/foobar'
# Prevent pushing this gem to RubyGems.org by setting 'allowed_push_host', or
# delete this section to allow pushing this gem to any host.
if spec.respond_to?(:metadata)
spec.metadata['allowed_push_host'] = 'http://mygemserver.com'
else
raise 'RubyGems 2.0 or newer is required to protect against public gem pushes.'
end
spec.files = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
spec.bindir = 'exe'
spec.executables = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
spec.require_paths = ['lib']
spec.add_development_dependency 'bundler', '~> 1.10'
spec.add_development_dependency 'rake', '~> 10.0'
spec.add_development_dependency 'rspec'
spec.add_dependency 'selenium-webdriver'
end
Environments
% rake --version
rake, version 11.1.2
% bundle --version
Bundler version 1.10.3
% ruby -v
ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-darwin13]
Is there any idea what causes this error?

Answer 1

I'm not sure what causes this error, but by updating the version of my gem the error don't occur anymore.