Merge branch 'maint-0.3.3' into maint-0.3.4

  o Minor bugfixes (tests):

    - Treat backtrace test failures as expected on BSD-derived systems

      (NetBSD, OpenBSD, and macOS/Darwin) until we solve bug 17808.

      (FreeBSD failures have been treated as expected since 18204 in 0.2.8.)

      Fixes bug 27948; bugfix on 0.2.5.2-alpha.

for l in LINES:

    print("{}".format(l), end="")

if sys.platform.startswith('freebsd'):

    # See bug #17808 if you know how to fix this.

    print("Test failed; but FreeBSD is known to have backtrace problems.\n"

          "Treating as 'SKIP'.")

if (sys.platform.startswith('freebsd') or sys.platform.startswith('netbsd') or

    sys.platform.startswith('openbsd') or sys.platform.startswith('darwin')):

    # See bug #17808 if you know how to fix backtraces on BSD-derived systems

    print("Test failed; but {} is known to have backtrace problems."

          .format(sys.platform))

    print("Treating as 'SKIP'.")

    sys.exit(77)

sys.exit(1)