I changed RUBYOPT to be empty, as someone suggested, with no change in
performance.

As a reminder, a plain numeric test runs about the same as Chet's
laptop. running the ruby tests as shown below is taking 15x longer on
my machine. 

To find out what's happening, I've been trying to figure out how to
make the test command

  ruby runner.rb ruby

trace which tests are running, thinking that since some of the dots
take forever to come out and some come out quickly, that might be
interesting information, and lead to some understanding of what is
going on.

sorry to be so ignorant, but what reformulation of that command would
run the tests named "ruby" and display some test names instead of just
dots?

Thanks,

Ron Jeffries
www.XProgramming.com