It is possible that your version of python is incompatible with the one we use to build Trelis? We are using the default that came with Mac OS X (Mavericks):
Python 2.7.5 (default, Mar 9 2014, 22:15:05)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
I should also note that it is 64-bit. In order for your version of python to be compatible, it needs to have the same major and minor version (which it seems you do), and also the same bitness (64-bit). I wonder if the python that your installed through homebrew is 32-bit and not 64-bit, so you might check that. If it doesn’t show up when you start python, you can always find it by doing this in python:
I am running into this same issue with Trelis 16.2 and MacOS 10.15.4 (Catalina). I’ve tried using Python 2.7.10 and have the same issue. Has there been any development to upgrade the python version that Trelis is compiled with?