make configure-macosx and make went well, (I did not changed anything in the source files, that is great): At that stage, I could launch Therion or Xtherion locally, they work well.
However, I faced some problems with sudo make install: I had an error because of writing permissions in usr/bin/. I am not a Macos guru, but if I good understood, from El Capitan, we do not have access to usr/bin/ even with a root login. I thus changed the makeinstall.tcl to copy the exec files to /usr/local/bin (Homebrew folder) for the macosx version (L30 to L33). I made some basics tests, and it seems working well. I opened a pull request for that in case it is relevant for all mac users.
For the loch install, I had the same problem, even with a « sudo make install » I have permissions errors to write in the folder /Applications/. I needed to 1) I need to edit the loch.app/Contents/ by creating a new MacOs Folder 2) copy the loch file to loch.app/Contents/MacOs/ and to copy manually the loch.app to /Applications/. I do not know if there is a way to automate that. I have not changed anything in the makeinstall.tcl for that.