Projucer preserve local changes leads to unknown type

JUCE 4.1, Mac 10.11.3

I've tweaked a number of things in the JUCE modules, mostly iOS stuff. In order to preserve these changes I've enabled "Preserve Local Module Changes" in Projucer so that they aren't overwritten every time I save my project in Projucer. However, now when I try to compile in XCode I get the following errors:

In JuceHeader.h

/Users/Joe/Developer/syntorial/Syntorial/JuceLibraryCode/JuceHeader.h:22:18: Expected namespace name

Followed by various "unknown type" errors for several JUCE classes like String, AudioPlayhead, etc

Am I misunderstanding how this is supposed to work or is this a Projucer bug?

If you don't let it update the modules then presumably something is out of date and no longer compatible. But I've no idea what's at line 22 of that file on your machine, so can't guess what the error means..

The whole local module copy thing is something we'll probably phase out soon as it creates a lot more problems than it solves. I'd recommend using your own copy of the juce git repo, so that when we change it, you can pull the new changes and GIT will take care of merging our changes with your own mods.

Will do. Thnx.