Issue #11540 has been reported by Martin Drst.

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Bug #11540: Certificate error (for minitest?)
https://bugs.ruby-lang.org/issues/11540

* Author: Martin Drst
* Status: Open
* Priority: Normal
* Assignee: Ryan Davis
* ruby -v: ruby 2.3.0dev (2015-09-17 trunk 51886) [x86_64-cygwin]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
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With the command 'make up', I get the following error.

Downloading bundled gem files...
power_assert-0.2.4.gem already exists
test-unit-3.1.3.gem already exists
downloading minitest-5.8.0.gem ... done
certificate /CN=ryand-ruby/DC=zenspider/DC=com not valid after 2015-09-17 23:07:07 UTC
rake-10.4.2.gem already exists



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