Disabling PCTools’ Spyware Doctor is the fix.

It appears that there’s an interaction between subversion, python and Spyware Doctor.  And the internet connection for this particular machine can be a little spotty (which sends most software down less-tested paths): I noticed that the regression test’s check-out retries were kicking in, too.

If I run subversion on its own, it works fine. Likewise python simulating a subversion-type operation (from within the regression test’s own scripts). It seems all three together are the trouble.

FYI.

See: http://lists.boost.org/boost-testing/2010/08/6668.php