I found an apparent dependency problem in Cygwin, and I'm not enough of a
Cygwin expert to know whether the bug is in Cygwin or Bazaar (Package
"bzr"); but if I had to guess, I'd guess it's in Cygwin, and I've already
reported the issue to the Bazaar forum.

In summary, after I installed Cygwin and Cygwin-Package "bzr", bzr failed
as it attempted to execute "python27". A detailed description of the issue,
including input and output from several tests I ran, and including the
solution posted by someone else (solution = install Cygwin-Package
"python27") is here, https://answers.launchpad.net/bzr/+question/691381,
and it's rather concise so I'll end here and refer you to that thread.

Per the directions here, https://cygwin.com/problems.html, I'm
email-attaching the output from "cygcheck -s -v -r".