"LearnCircuitBuildTimeout 0" is broken when no CircuitBuildTimeout is set
Tor, when compiled with --enable-tor2web-mode and a torrc with Tor2webMode enabled has trouble establishing a directory connection.
Steps to reproduce: build Tor with --enable-tor2web-mode, set the Tor2webMode 1 option in torrc and start Tor.
Sometimes it hangs at 10% (Establishing directory connection), other times it hangs at 45% (Asking for relay descriptors)