Dear Daniel,

Thanks for the report and suggestion.
We also note about the github link.

Correct me if I am wrong, but the script is to build the macosx version of EiffelStudio, and not the "linux-x86-64" .
So the correct value for ISE_PLATFORM should be "macosx-x86-64" 

I haven't checked carefully the full diff associated with the github link. 
Without deeper investigation, I would say  if you build EiffelStudio for macosx, then you should use "macosx-x86-64", and not "linux-..."