start fails with "Control port file not created"

Start log observed on Android 4.4.4, Tor Browser 60.6.1, 100% failure rate:

- Set background service to FOREGROUND
- updating settings in Tor service
- updating torrc custom configuration...
- success.
- checking binary version: 0.3.5.8-rc-openssl1.0.2p
- Orbot is starting…
- Tor control port file not created
- Unable to start Tor: java.io.IOException: Control port file not created: /data/data/org.torproject.torbrowser_alpha/app_torservice/lib/tor/control.txt, len = 0

I've seen two mentions of this by Google search, but couldn't find an existing ticket.

Trac:
Username: belm0