bin/autoproj_bootstrap in autoproj-1.9.3.rc5 vs bin/autoproj_bootstrap in autoproj-1.9.3.rc6

@@ -52,10 +52,11 @@
     if ENV['GEM_HOME'] != needed_gem_home
         require 'rbconfig'
         RUBY = RbConfig::CONFIG['RUBY_INSTALL_NAME']
 
         ENV['GEM_HOME'] = needed_gem_home
+        ENV.delete 'GEM_PATH'
         exec RUBY, __FILE__, *ARGV
     end
 end
 
 
@@ -521,10 +522,10 @@
                     if !installed.empty? && Autobuild.do_update
                         # Look if we can update the package ...
                         dep = Gem::Dependency.new(name, version_requirements)
                         available =
                             if gem_fetcher.respond_to?(:find_matching)
-                                gem_fetcher.find_matching(dep).map(&:first)
+                                gem_fetcher.find_matching(dep, true, true, GemManager.with_prerelease).map(&:first)
                             else # Post RubyGems-2.0
                                 type = if GemManager.with_prerelease then :prerelease
                                        else :complete
                                        end