Today I updated my ruby core clone, and I run the usual steps to compile ruby. When running "make", I run into the following error: ``` (... stuff ...) encdb.h unchanged Traceback (most recent call last): 5: from ./tool/mkconfig.rb:19:in `<main>' 4: from ./tool/mkconfig.rb:19:in `require' 3: from /home/deivid/Code/ruby/lib/fileutils.rb:4:in `<top (required)>' 2: from /home/deivid/Code/ruby/lib/fileutils.rb:4:in `require' 1: from /home/deivid/Code/ruby/rbconfig.rb:11:in `<top (required)>' /home/deivid/Code/ruby/rbconfig.rb:13:in `<module:RbConfig>': ruby lib version (2.5.0) doesn't match executable version (2.6.0) (RuntimeError) uncommon.mk:780: recipe for target '.rbconfig.time' failed make: *** [.rbconfig.time] Error 1 ``` Apparently, the script that generates the root `rbconfig.rb` file requires `fileutils`, which in turn requires 'rbconfig' (for mjit-headers it says in a comment), which uses the `rbconfig.rb` config file in the root folder if it exists. In my case, this file existed but had been generated on 2.5.0, thus causing the error. I think we can avoid this sort of circular dependency by not requiring `fileutils`, since it does not seem to be used anywhere in the `tool/mkconfig.rb` script since r55338. [Fix GH-2045] From: David Rodríguez <[email protected]> git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66301 b2dd03c8-39d4-4d8f-98ff-823fe69b080e