Description of problem:
I get a problem when trying to make check subversion (arch ppc64le)
Problem occurs during make check-swig-rb

Version-Release number of selected component (if applicable):
subversion-1.8.8-1.fc21
rubygem-minitest-5.3.1-1.fc21
ruby-2.0.0.353-18.fc21 

How reproducible:
always by running
rpmbuild with make check enabled
executing `make check-swig-rb' from the top of the Subversion build tree

Actual results:
if [ "LD_LIBRARY_PATH" = "DYLD_LIBRARY_PATH" ]; then for d in /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby/libsvn_swig_ruby /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby/../../../libsvn_*; do if [ -n "$DYLD_LIBRARY_PATH" ]; then LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$d/.libs"; else LD_LIBRARY_PATH="$d/.libs"; fi; done; export LD_LIBRARY_PATH; fi; \
cd /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby; \
          if [ "2" -eq 1 -a "0" -lt 9 ] ; then \
            /usr/bin/ruby -I /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby \
              /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby/test/run-test.rb \
      --verbose=verbose; \
          else \
    /usr/bin/ruby -I /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby \
      /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby/test/run-test.rb; \
          fi
Warning: you should require 'minitest/autorun' instead.
Warning: or add 'gem "minitest"' before 'require "minitest/autorun"'
From:
  /usr/share/ruby/test/unit.rb:3:in `<top (required)>'
  /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby/test/run-test.rb:22:in `<main>'
MiniTest::Unit::TestCase is now Minitest::Test. From /usr/share/ruby/test/unit/testcase.rb:8:in `<module:Unit>'
/usr/share/ruby/test/unit.rb:670:in `<class:Runner>': undefined method `_run_suite' for class `Test::Unit::Runner' (NameError)
        from /usr/share/ruby/test/unit.rb:255:in `<module:Unit>'
        from /usr/share/ruby/test/unit.rb:9:in `<module:Test>'
        from /usr/share/ruby/test/unit.rb:8:in `<top (required)>'
        from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
        from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
        from /builddir/build/BUILD/subversion-1.8.8/subversion/bindings/swig/ruby/test/run-test.rb:22:in `<main>'
make: *** [check-swig-rb] Error 1

Additional info:
it seems that minitest 5 and test/unit are no more compatible.
please have look to https://github.com/seattlerb/minitest/issues/283