Fail to clone github repo on the host machine
Your host key can be invalidated due to OS re-installation or IP address re-assign.
If that’s the case, you must refresh
sudo su - dokku # become dokku user
ssh-keygen -R github.com # delete github.com entry
ssh -T email@example.com # verify ssh connection
You will see a successful build after you run the CI build. such as Github Action.