As the successor to the deprecated databases/py-rrdtool_lgpl port [1], this port is intended to inherit its functionality, but comes from a different source [2][3] and is also named differently.
[1] https://sourceforge.net/projects/py-rrdtool/files/
[2] http://www.nongnu.org/py-rrdtool/
[3] https://github.com/commx/python-rrdtool
The original patch is from Darius, after discussion with several people (including Gleb) somewhat revised by me.
Submitted by darius@dons.net.au (new maintainer) in PR 251126.
Tested on Poudriere (amd64, i386). 'portlint -AC' is fine.