Build fails on Linux; ofxTimeline addon ignored by build system?

[egasimus]

Having cloned everything according to the README, running make in openFrameworks/apps/Duration/Duration terminates with:
src/DurationController.h:37:25: fatal error: ofxTimeline.h: No such file or directory #include "ofxTimeline.h"

Setting PROJECT_CFLAGS = -I../../../addons/ofxTimeline/src results in:

In file included from src/DurationController.h:43:0, from src/DurationController.cpp:33: ../../../addons/ofxTimeline/src/ofxTLAudioTrack.h:37:51: fatal error: ofOpenALSoundPlayer_TimelineAdditions.h: No such file or directory #include "ofOpenALSoundPlayer_TimelineAdditions.h"

Setting PROJECT_CFLAGS = -I../../../addons/ofxTimeline/src -I../../../addons/ofxTimeline/libs/ofOpenALSoundPlayer_TimelineAdditions/src moves things forward, but eventually results in a huge list of linker errors.

There seem to be no object files from ofxTimeline in the list of linker options, and since they don't seem to be built by the Duration makefile, I can't manually add them to PROJECT_LDFLAGS like I did with the includes. How do I build Duration?

[tommag]

It's a little late, but may be useful to others...
I found that by commenting out all blank lines (ADDON_INCLUDES =, ADDON_CFLAGS =, etc) in addons/ofxTimeline/addon_config.mk the right include paths are added automatically.