MAKEWHATIS_TEST(MDOC) MDOC MAKEWHATIS_TEST(MDOC)

real/makewhatis_test
test makewhatis(8) and apropos(1)

Choose a manual tree you are maintaining or care about. Run makewhatis(8) on it. Try out various apropos(1) features and try to discover issues. Report any you find to me.

For this exercise, having an up-to-date mandoc suite is more important than for most. Consider checking out from anoncvs@mdocml.bsd.lv:/cvs and building and installing from that before starting. On OpenBSD, it is better to build from /usr/src/usr.bin/mandoc instead.
To run makewhatis(8) on one specific tree only, you will need the dir argument.
If everythings appears to be working fine, try to refine your methods. For example, try the -p, -D, and -DD options of makewhatis(8) and try to understand the output.
Probably, most of the output will be false positives, but you may also find some real bugs in the manuals in this way that can be worth patching.
If you are comfortable with SQL, run the sqlite3(1) command line client directly on the database generated by makewhatis(8) and look for anything that seems questionable.
September 26, 2014 bsd.lv