Debugging experiment for Emscripten buildbot.

[freakboy3742]

Adds debug to the pydoc empty apropos test in the hope of working out why it's failing, but only in CI..

[freakboy3742]

!buildbot emscripten

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @freakboy3742 for commit 76481cb 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F136718%2Fmerge

The command will test the builders whose names match following regular expression: emscripten

The builders matched are:

• WASM Emscripten PR

[freakboy3742]

!buildbot emscripten

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @freakboy3742 for commit dd7a19e 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F136718%2Fmerge

The command will test the builders whose names match following regular expression: emscripten

The builders matched are:

• WASM Emscripten PR

[freakboy3742]

Problem found: the buildbots run with a 0o77 umask; when combined with an edge case bug in Emscripten's readdir implementation, and a very suspect chmod call in the test in question, behavior in the test was different.