error in building ("make -j" step) with Ubuntu 20.04LTS

Hi
For Ubuntu 20.04 LTS, if I use gfortran-9, the `cmake` step is OK,

But when I `make -j`, I've got an error when building EbsdLib. The log say :
```
In file included from /donnees/Linux/EMsoft/EMsoft_SDK/superbuild/EbsdLib/Source/EbsdLib/Source/EbsdLib/IO/AngleFileLoader.cpp:44:
/donnees/Linux/EMsoft/EMsoft_SDK/superbuild/EbsdLib/Source/EbsdLib/Source/EbsdLib/Core/Orientation.hpp:761:9: error: extended character ∂ is not valid in an identifier
761 | Q_∂(false);
| ^
```
I didn't put all the .log file, but this error is repeted a large number of times, for each crystal symmetry (orthorombic, hexagonal, cubic...)

Thanks