accept a reasonably live consensus for path selection
When I fixed guard selection in #24661 (moved), tor said:
Nov 05 15:29:55.000 [notice] I learned some more directory information, but not enough to build a circuit: We have no recent usable consensus.
Maybe this is a logging issue, maybe it's another constraint we need to fix.
See the full log in: https://trac.torproject.org/projects/tor/ticket/24661#comment:13