Downgrade/install graphviz 2.38.0 via MacPorts to resolve PlantUML issues

fix-graphviz-for-PlantUML.sh

#!/bin/bash

# PlantUML has "a lot of issues" with graphviz greater 2.38.0 (screwed up layouts and more, check the official PlantUML site)
# so we need to get the old port file
# I tested this with Mac OS 10.15.6

# the update to 2.40.1 was done by this commit https://github.com/macports/macports-ports/commit/937422eaee9e592a79b631ee20cecdbbe33a7375, so the parent on the master is c11df6b3e4867171fff9438ba499e20f31b449e8

# uninstall the current version first - note this might break other things ;-)
sudo port uninstall graphviz

# get the old port file
cd /tmp
git clone --single-branch https://github.com/macports/macports-ports.git
cd macports-ports
git checkout c11df6b3e4867171fff9438ba499e20f31b449e8

# the 2.38.0 distribution is not available from the location defined in the portfile anymore
# additionally also the graphviz.org official site does not provide the tar.gz anymore (http://graphviz.org/download/)
# I found a mirror at http://mirror.pnl.gov/macports/distfiles/graphviz/
# (checksums will be checked, don't panic) 
# add that mirror to the portfile
echo "master_sites                    http://mirror.pnl.gov/macports/distfiles/graphviz/" >> ./Portfile

# install from here
cd graphics/graphviz
sudo port install

# celanup
rm -rf /tmp/macports-ports

Executing

bash <(curl -s https://gist.githubusercontent.com/hgross/67ea67c4fdcf5636ee2dd96e35a154b8/raw/362d4fc62f2ea65adfa07a139178f3e8ab80aa93/fix-graphviz-for-PlantUML.sh)

from the Terminal should do the trick and install Graphviz 2.38.0 on Mac OS 10.15.6 via MacPorts.