I believe that I found a resolution - the issue lies with compiler versions not quite working. Adding version 9 as alternatives, selecting them then recompiling fixed the issue for me. Steps:
$ sudo apt-get install g++-9
$ sudo apt-get install gcc-9
$ sudo apt-get install gfortran-9
$ sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-9 50
$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-9 50
$ sudo update-alternatives --install /usr/bin/gfortran gfortran /usr/bin/gfortran-9 50
$ sudo update-alternatives --config g++ {then select the option for 9}
$ sudo update-alternatives --config gcc {then select the option for 9}
$ sudo update-alternatives --config gfortran {then select the option for 9}
in the plasticity directory:
$ rm -rf CMakeCache.txt applications/crystalPlasticity/CMakeCache.txt
$ cmake .
$ make -j 4
$ cd applications/crystalPlasticity
$ cmake .
$ make release
This worked for me, please let me know if this solution didn't help.
Michael