I installed the latest version of lightGBM(lgb.__version__ == '2.2.1') which is supported by gcc8, but now I have a model already built with lightgbm==2.0.2 which is supported by gcc7. 
I need to conform with the previous version, which means I have to downgrade current version of lightgbm, using pip install lightgbm==2.0.2, however when I import it, I met Library not loaded: /usr/local/opt/gcc/lib/gcc/7/libgomp.1.dylib. 
I have checked here and here, the problem is I must use lightgbm of previous version. 
I assume the problem is caused by gcc version, so is there a way I can install gcc 7?(by the way I tried create a virtualenv on my computer so that I can have both version of lightgbm, also can I install gcc 7 under the virtual environment and keep gcc 8 on my computer as well?)
Thanks soooo much!
 
    