add found manifests to multiple manifests warning

Author: michaelglass

lib/sprockets/manifest_utils.rb

@@ -38,7 +38,7 @@ def find_directory_manifest(dirname, logger = Logger.new($stderr))
       entries = File.directory?(dirname) ? Dir.entries(dirname) : []
       manifest_entries = entries.select { |e| e =~ MANIFEST_RE }
       if manifest_entries.length > 1
-        logger.warn('Found multiple manifests. Choosing the first alphabetically.')
+        logger.warn("Found multiple manifests: #{manifest_entries}. Choosing the first alphabetically: #{manifest_entries.first}")
       end
       entry = manifest_entries.first || generate_manifest_path
       File.join(dirname, entry)

test/test_manifest_utils.rb

@@ -32,6 +32,6 @@ def test_warn_on_two
       find_directory_manifest("#{root}/with_two_manifests", logger)
     output = r.gets
 
-    assert_match(/W, \[[^\]]+\]  WARN -- : Found multiple manifests. Choosing the first alphabetically/, output)
+    assert_match(/W, \[[^\]]+\]  WARN -- : Found multiple manifests: .+ Choosing the first alphabetically: \.sprockets-manifest-00000000000000000000000000000000\.json/, output)
   end
 end