Poco::FastMutex not available on master

I wanted to upgrade from stable to master branch, but it’s not possible to generate a new project using Poco::FastMutex for me. With the release version 0.9.8 it’s working.
Test ofApp.h:

...
Poco::FastMutex ourMutex;
...

I tried the generator-vs the release and nightly build (v20170714) version, but the lib poco was not included correctly.

The download script worked properly, so the lib is available.

you can use:

ofThread ourMutex;

or

std::thread ourMutex;

or

std::mutex;

? In that case .tryLock(2000); becomes .try_lock().

I found that suggestion at Building for android: problems with Poco