Commit  b9a1a1f  is a revert of commit  8df9a22 , differing only in the comment.
This means the issue from mruby#6721 has reappeared.
The cause of mruby#6721, as stated in the commit message for commit  8df9a22 , is that each ".o" file has an indirect dependency on all ".pi" files through the presym file.
This patch therefore adds a proxy-like task `gensym:update:#{build.name}` between tasks.
Its purpose is to hide the direct dependency from ".o" files to the presym file from the rake system.

dearblue marked this pull request as ready for review