18537, "cassella", "prereqs.rst doesn't note doxygen required for docs builds", "2021-10-08T05:21:58Z"
doc/rst/usingchapel/prereqs.rst doesn't mention doxygen, but it's required in order to run make docs. Unlless I got things into a bad state by running (as directed by make output),
make clobber-libchplcomp && make libchplcomp-docs
I don't know if the doc would need any requirements on the version.