I managed to install Cabbage in ubuntu 19.04 with JUCE 5.4.3 and a old VST SDK (for vst2 headers)
cabbageLite compiled ok but CabbageIDE had a problem in CabbageDocumentWindow.cpp
pluginExporter.settingsToUse(cabbageSettings->getUserSettings()); was generating a compiler error (method not present in pluginExporter.
I commented the line, everything seem fine, but may be it’s not the cause of the problem ?
It’s decalred on line 34 of CabbageExportPlugin.h? Can you double check it’s there? I can’t think of any reason it wouldn’t be…
in cabbage 2.2.0 it’s not present, I see it’s in the repository, is the master in git stable enough for a newbie ? 
The dev branch should be stable enough for a newbie! The dev branch is rarely ever broken.
I’m trying with the dev branch, and JUCE 5.4.4,
now it’s complaining that it can’t find gtk/gtk.h. I added a “/usr/include/gtk-3.0” to the CabbageIDE.juce, and generated a Makefile.
Seems to work but it doesn’t seem to be the right thing to do ?
Or install the very latest gtk stuff. I think there is a mention of which package is need on the JUCE forums. Many people get caught out with that one.