Examples I have been able to find suggest the following for an exclusion:
covselect --add \!/usr/src/thing/to/exclude
However, when I do this, and list my inclusions, I get:
BullseyeCoverage Select Regions 8.8.9 Linux-x64 License 9395
Copyright (c) Bullseye Testing Technology 1990-2013
include folder /usr/src/
include folder /!/usr/src/thing/to/exclude/
?