TST: add test for discovery import failures
TST: add test for discovery import failures

spacetelescope/asv,airspeed-velocity/asv,qwhelan/asv,spacetelescope/asv,spacetelescope/asv,qwhelan/asv,airspeed-velocity/asv,qwhelan/asv,spacetelescope/asv,airspeed-velocity/asv,qwhelan/asv,airspeed-velocity/asv