When did you download the CHARMM source?
What were the commands used to build CHARMM?
The threads you referenced were using the older, deprecated ./install.com procedure, while "installing CHARMM for Ubuntu" link uses the newer ./configure procedure, so those threads may not be relevant. If you used configure, there should be messages about any problems encountered. Did you install Ubuntu cmake first, or use the one that configure builds from source?
Please verify your compiler and cmake versions via
The gfortran version should match gcc; gfortran and cmake may not be installed on Ubuntu by default.
Martin Karplus spent some time in Strasbourg, so perhaps there are people there you could ask for help.
From the main charmm directory (c45b1 in my case), I did the following: