only define gem packaging tasks if rubygems is already loaded

Rakefile

@@ -5,6 +5,11 @@ require 'fileutils'
 task :default => :test
 task :spec => :test
 
+def source_version
+  line = File.read('lib/sinatra/base.rb')[/^\s*VERSION = .*/]
+  line.match(/.*VERSION = '(.*)'/)[1]
+end
+
 # SPECS ===============================================================
 
 Rake::TestTask.new(:test) do |t|
@@ -12,50 +17,23 @@ Rake::TestTask.new(:test) do |t|
   t.ruby_opts = ['-rubygems -I.'] if defined? Gem
 end
 
-# PACKAGING ============================================================
+# Rcov ================================================================
-
+namespace :test do
-# Load the gemspec using the same limitations as github
+  desc 'Mesures test coverage'
-def spec
+  task :coverage do
-  require 'rubygems' unless defined? Gem::Specification
+    rm_f "coverage"
-  @spec ||= eval(File.read('sinatra.gemspec'))
+    rcov = "rcov --text-summary --test-unit-only -Ilib"
+    system("#{rcov} --no-html --no-color test/*_test.rb")
+  end
 end
 
-def package(ext='')
+# Website =============================================================
-  "pkg/sinatra-#{spec.version}" + ext
-end
-
-desc 'Build packages'
-task :package => %w[.gem .tar.gz].map {|e| package(e)}
-
-desc 'Build and install as local gem'
-task :install => package('.gem') do
-  sh "gem install #{package('.gem')}"
-end
-
-directory 'pkg/'
-CLOBBER.include('pkg')
-
-file package('.gem') => %w[pkg/ sinatra.gemspec] + spec.files do |f|
-  sh "gem build sinatra.gemspec"
-  mv File.basename(f.name), f.name
-end
-
-file package('.tar.gz') => %w[pkg/] + spec.files do |f|
-  sh <<-SH
-    git archive \
-      --prefix=sinatra-#{source_version}/ \
-      --format=tar \
-      HEAD | gzip > #{f.name}
-  SH
-end
-
-# Website ============================================================
 # Building docs requires HAML and the hanna gem:
 #   gem install mislav-hanna --source=http://gems.github.com
 
+desc 'Generate RDoc under doc/api'
 task 'doc'     => ['doc:api']
 
-desc 'Generate Hanna RDoc under doc/api'
 task 'doc:api' => ['doc/api/index.html']
 
 file 'doc/api/index.html' => FileList['lib/**/*.rb','README.rdoc'] do |f|
@@ -73,41 +51,63 @@ file 'doc/api/index.html' => FileList['lib/**/*.rb','README.rdoc'] do |f|
 end
 CLEAN.include 'doc/api'
 
-# Gemspec Helpers ====================================================
+# PACKAGING ============================================================
 
-def source_version
+if defined?(Gem)
-  line = File.read('lib/sinatra/base.rb')[/^\s*VERSION = .*/]
+  # Load the gemspec using the same limitations as github
-  line.match(/.*VERSION = '(.*)'/)[1]
+  def spec
-end
+    require 'rubygems' unless defined? Gem::Specification
+    @spec ||= eval(File.read('sinatra.gemspec'))
+  end
 
-task 'sinatra.gemspec' => FileList['{lib,test,compat}/**','Rakefile','CHANGES','*.rdoc'] do |f|
+  def package(ext='')
-  # read spec file and split out manifest section
+    "pkg/sinatra-#{spec.version}" + ext
-  spec = File.read(f.name)
+  end
-  head, manifest, tail = spec.split("  # = MANIFEST =\n")
-  # replace version and date
-  head.sub!(/\.version = '.*'/, ".version = '#{source_version}'")
-  head.sub!(/\.date = '.*'/, ".date = '#{Date.today.to_s}'")
-  # determine file list from git ls-files
-  files = `git ls-files`.
-    split("\n").
-    sort.
-    reject{ |file| file =~ /^\./ }.
-    reject { |file| file =~ /^doc/ }.
-    map{ |file| "    #{file}" }.
-    join("\n")
-  # piece file back together and write...
-  manifest = "  s.files = %w[\n#{files}\n  ]\n"
-  spec = [head,manifest,tail].join("  # = MANIFEST =\n")
-  File.open(f.name, 'w') { |io| io.write(spec) }
-  puts "updated #{f.name}"
-end
 
-# Rcov ==============================================================
+  desc 'Build packages'
-namespace :test do
+  task :package => %w[.gem .tar.gz].map {|e| package(e)}
-  desc 'Mesures test coverage'
+
-  task :coverage do
+  desc 'Build and install as local gem'
-    rm_f "coverage"
+  task :install => package('.gem') do
-    rcov = "rcov --text-summary --test-unit-only -Ilib"
+    sh "gem install #{package('.gem')}"
-    system("#{rcov} --no-html --no-color test/*_test.rb")
+  end
+
+  directory 'pkg/'
+  CLOBBER.include('pkg')
+
+  file package('.gem') => %w[pkg/ sinatra.gemspec] + spec.files do |f|
+    sh "gem build sinatra.gemspec"
+    mv File.basename(f.name), f.name
+  end
+
+  file package('.tar.gz') => %w[pkg/] + spec.files do |f|
+    sh <<-SH
+      git archive \
+        --prefix=sinatra-#{source_version}/ \
+        --format=tar \
+        HEAD | gzip > #{f.name}
+    SH
+  end
+
+  task 'sinatra.gemspec' => FileList['{lib,test,compat}/**','Rakefile','CHANGES','*.rdoc'] do |f|
+    # read spec file and split out manifest section
+    spec = File.read(f.name)
+    head, manifest, tail = spec.split("  # = MANIFEST =\n")
+    # replace version and date
+    head.sub!(/\.version = '.*'/, ".version = '#{source_version}'")
+    head.sub!(/\.date = '.*'/, ".date = '#{Date.today.to_s}'")
+    # determine file list from git ls-files
+    files = `git ls-files`.
+      split("\n").
+      sort.
+      reject{ |file| file =~ /^\./ }.
+      reject { |file| file =~ /^doc/ }.
+      map{ |file| "    #{file}" }.
+      join("\n")
+    # piece file back together and write...
+    manifest = "  s.files = %w[\n#{files}\n  ]\n"
+    spec = [head,manifest,tail].join("  # = MANIFEST =\n")
+    File.open(f.name, 'w') { |io| io.write(spec) }
+    puts "updated #{f.name}"
   end
 end