This is using a branch from my personal github clone of TeXmacs. It is using the cmake build system. For some reason, there are no MacOS dialog boxes shown when trying to save-as or export to pdf. The temporary workaround is to open the file you plan to edit using the command line. When you do that, the F3 key and "save" menu item work to save the file. To convert it to a PDF, again use the command line, like: