Symptoms
Ubuntu servers fail to install cPanel after an in-place OS upgrade has taken place with the following error:
Can't exec "/bin/dpkg": No such file or directory at ./fix-cpanel-perl line 338.
Description
The cPanel installation script executes dpkg via /bin/dpkg. On most operating systems, this is symbolically linked to /usr/bin/dpkg; however, this is not the case on Ubuntu servers without the usrmerge package installed.
cPanel requires a newly created installation of Ubuntu 20.04. In-place upgrades from previous versions of Ubuntu will encounter errors such as this one shown above and are not supported by cPanel.
Workaround
Your server must use a clean installation of Ubuntu 20.04 LTS.