AliBuild O2 failis: GL/gl3w.h: No such file or directory

Dear all,

Even though file ./GPU/GPUTracking/Standalone/display/3rdparty/GL/gl3w.h is present in my O2 tree, the compilation is failing with the following error message

In file included from /home/rafael/alice/sw/SOURCES/O2/v1.2.0/0/GPU/GPUTracking/Standalone/display/GPUDisplay.h:20:0,
                 from /home/rafael/alice/sw/SOURCES/O2/v1.2.0/0/GPU/GPUTracking/Standalone/display/GPUDisplayBackend.cxx:15:
/home/rafael/alice/sw/SOURCES/O2/v1.2.0/0/GPU/GPUTracking/Standalone/display/GPUDisplayExt.h:25:10: fatal error: GL/gl3w.h: No such file or directory
 #include "GL/gl3w.h"
      ^~~~~~~~~~~

alidist has been properly updated. I am using Debian 9.

Any tip on what may be wrong?

Thanks in advance,
Rafael