Problem

You want to install asdf in a new (k)ubuntu installation but some of the plugins are not installed (python).

Solution

Make sure you install the dependencies first

sudo apt install -y build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev xz-utils tk-dev libffi-dev liblzma-dev python3-openssl git