Use dpkg-buildpackage, the python3-grpc-tools and python3-grpcio versions in those repos are fine

Add this PPA to satisfy dependencies (for the time being):

https://launchpad.net/~clementlefebvre/+archive/ubuntu/grpc?field.series_filter=bionic

meson builddir --prefix=/usr  (I think it needs to be /usr for gobject introspection to work).
ninja -C builddir
sudo ninja -C builddir install

• meson (>= 0.45.0)
• python3-grpc-tools (>= 1.14.0)
• python3-protobuf (>= 3.6.1)
• gobject-introspection

• gir1.2-glib-2.0
• gir1.2-gtk-3.0 (>= 3.20.0)
• gir1.2-xapp-1.0 (>= 1.6.0)
• python3
• python3-gi
• python3-setproctitle
• python3-xapp (>= 1.6.0)
• python3-zeroconf
• python3-grpcio (>= 1.16.0)
• python3-cryptography
• python3-nacl

pip3 install grpcio grpcio-tools