I encountered with this problem When I try to build ArdcuCopter v3.6_dev source code.
What is this problem. I follow all steps from developer wiki-page . Did I skipped a step or What ?
OS : Ubuntu 16.04
Thanks for your help and time
Error msg clearly state that You dont have python package em, even here is noted command to install it.
I saw the notes . I already applied previous . The result is same
How I can remember when someone had problem with future/lxml packages, when they were already installed, re-install helped them. Try to remove python-empy package and install again.
pip uninstall em
pip install empy
This looks familiar
Thanks for help. This solve my problem