0.9.8 msys2 on Windows - doesn't find addons

Just installed the msys2 0.9.8 release on Windows 8.1.

Couldn’t compile an app, because it didn’t find the addon.
It gives the usual “fatal error: foo.h: No such file or directory”

Then I tried to run buildAllExamples.sh (using MINGW32) and noticed it failed with all the examples that use addons, yet succeeded with the rest.