Manual tortoisehg installation (if required):
https://askubuntu.com/questions/1182598/how-to-install-tortoisehg-on-ubuntu-19-10
https://askubuntu.com/questions/1232173/how-to-install-the-tortoisehg-in-ubuntu20-04

mkdir ~/temp 2>/dev/null
cd ~/temp
sudo apt install python-is-python3
python --version
sudo apt install -y python3-pip build-essential
sudo apt install -y mercurial
hg clone https://bitbucket.org/tortoisehg/thg/ -r stable
hg clone https://foss.heptapod.net/mercurial/tortoisehg/thg -r stable
cd thg
pip3 install pyqt5
pip3 install qscintilla
sudo apt install -y pyqt5.qsci-dev
pip3 install mercurial
sudo apt install -y python3-iniparse
make local
cd ~/temp
rm -rf ~/tortoisehg 2>/dev/null
mkdir ~/tortoisehg
mv thg/* ~/tortoisehg
vi ~/.local/share/applications/tortoisehg.desktop
pip3 install qscintilla
sudo apt-get install python3-pyqt5.qsci