--- ruby-1.9.3-p0/lib/rubygems/uninstaller.rb.orig	2011-10-31 10:22:36.321579483 +0100
+++ ruby-1.9.3-p0/lib/rubygems/uninstaller.rb	2011-10-31 10:34:25.563626119 +0100
@@ -51,15 +51,14 @@
     @bin_dir           = options[:bin_dir]
     @format_executable = options[:format_executable]
 
+    if options[:force]
+      @force_all = true
+      @force_ignore = true
+    end
+
     # only add user directory if install_dir is not set
     @user_install = false
     @user_install = options[:user_install] unless options[:install_dir]
-
-    if @user_install then
-      Gem.use_paths Gem.user_dir, @gem_home
-    else
-      Gem.use_paths @gem_home
-    end
   end
 
   ##
@@ -69,10 +68,24 @@
   def uninstall
     list = Gem::Specification.find_all_by_name(@gem, @version)
 
+    list, other_repo_specs = list.partition do |spec|
+      @gem_home == spec.base_dir or
+      (@user_install and spec.base_dir == Gem.user_dir)
+    end
+
     if list.empty? then
-      raise Gem::InstallError, "gem #{@gem.inspect} is not installed"
+      raise Gem::InstallError, "gem #{@gem.inspect} is not installed" if
+        other_repo_specs.empty?
+
+      other_repos = other_repo_specs.map { |spec| spec.base_dir }.uniq
+
+      message = ["#{@gem} is not installed in GEM_HOME, try:"]
+      message.concat other_repos.map { |repo|
+        "\tgem uninstall -i #{repo} #{@gem}"
+      }
 
-    elsif list.size > 1 and @force_all then
+      raise Gem::InstallError, message.join("\n")
+    elsif @force_all then
       remove_all list
 
     elsif list.size > 1 then
@@ -250,12 +263,10 @@
     msg << "\t#{spec.full_name}"
 
     spec.dependent_gems.each do |dep_spec, dep, satlist|
-      msg <<
-        ("#{dep_spec.name}-#{dep_spec.version} depends on " +
-         "[#{dep.name} (#{dep.requirement})]")
+      msg << "#{dep_spec.name}-#{dep_spec.version} depends on #{dep}"
     end
 
-    msg << 'If you remove this gems, one or more dependencies will not be met.'
+    msg << 'If you remove this gem, one or more dependencies will not be met.'
     msg << 'Continue with Uninstall?'
     return ask_yes_no(msg.join("\n"), true)
   end

--- ruby-1.9.3-p0/test/rubygems/test_gem_uninstaller.rb.orig	2011-11-03 08:58:31.411272176 +0100
+++ ruby-1.9.3-p0/test/rubygems/test_gem_uninstaller.rb	2011-11-03 08:58:43.010272351 +0100
@@ -225,7 +225,7 @@
 
     uninstaller = Gem::Uninstaller.new('a')
 
-    use_ui Gem::MockGemUi.new("2\n") do
+    use_ui Gem::MockGemUi.new("2\ny\n") do
       uninstaller.uninstall
     end