Help with cad/netgen port

[Montgomery-Smith, Stephen]

I am the maintainer of the cad/netgen port, and I am having some
difficulties.  The fetch parts of Makefile is:

PORTNAME=       netgen
PORTVERSION=    6.2.2004
DISTVERSIONPREFIX=      v

USE_GITHUB=     yes
GH_ACCOUNT=     NGSolve
GH_PROJECT=     netgen:1 pybind11:2
GH_TAGNAME=     v${PORTVERSION}:1 v2.4.3:2
GH_SUBDIR=      external_dependencies/pybind11:2

When I perform "make makesum", the file distinfo lists
NGSolve-netgen-v6.2.2004_GH0.tar.gz twice.  This makes "make fetch" fail
until I edit out one of these entries.

Did I configure Makefile incorrectly, or is this a bug with "make makesum"?

Thanks, Stephen