I ran the bisects and at the end the report was:
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[8ed2110796b33df581aeb9a73ec491dd78d9902b] Fix static-check warnings.
I had a look at that commit and it doesn't, on the surface, seem to have anything to do with the error I'm seeing but who knows?
As a reminder - there are many errors displayed during the build but the first is:
Processing test/daemon/GPSmap-76S.log...gpsd:ERROR: shmget(1196446532, 8248, 0666) failed: Invalid argument
gpsd:ERROR: shared-segment creation failed,