Remember there are two kinds of variable. Internal Variables and Environment Variables. PATH should be an environment variable.
In my case, I was trying to debug
which asdf
not finding asdf, in a minimal shell.
I had checked
bash-5.1$ echo $PATH|grep asdf
/home/tyler/.asdf/bin
but ```
The PATH environment variable
env | /bin/grep PATH
``
being empty was the key discovery here. Must have forgotten the
export`.