From: "nobu (Nobuyoshi Nakada)" Date: 2013-02-22T10:35:55+09:00 Subject: [ruby-core:52668] [ruby-trunk - Bug #7897] rubygems 2.0 has an incompatibility about installation of extension libraries if gem package does not contain lib directory Issue #7897 has been updated by nobu (Nobuyoshi Nakada). It caused by r38864, which removes timestamp files in dependency rules. Now mkmf uses those files to fix parallel make issues. ---------------------------------------- Bug #7897: rubygems 2.0 has an incompatibility about installation of extension libraries if gem package does not contain lib directory https://bugs.ruby-lang.org/issues/7897#change-36754 Author: mrkn (Kenta Murata) Status: Assigned Priority: Urgent Assignee: nobu (Nobuyoshi Nakada) Category: lib Target version: 2.0.0 ruby -v: ruby 2.0.0dev (2013-02-08 trunk 39161) [x86_64-darwin11.4.2] Hi, rubygems 2.0 has an incompatibility about installation of extension libraries. If a gem package does not contain lib directory, an extension library file is copied as a file named "lib". You can reproduce this problem by installing msgpack version 0.4.7. -- http://bugs.ruby-lang.org/