module 'fes' has no attribute 'Handler'

[MaihgrUmosch]

I've followed the instructions to install fes. Using uptide commands leads to this error:

module 'fes' has no attribute 'Handler'

cmake commands were run from inside the firedrake virtual environment and the testing within the build folder ran successfully. How can it be confirmed that fes has installed correctly within the firedrake folders and is accessible by uptide?