Hi Mirek,

I downloaded and built upp-x11-src-12584. Looks like there's an issue with U++ & OpenGL, since when I build and run the "GLDrawDemo" from the U++ "reference" section, nothing renders.

The first issue that I ran into was the following, "ld: cannot find -libgtkglext-x11-1.0". Once addressed, I rebuilt and attempted to run the "GLDrawDemo" without luck.

Attached will be a tar.gz file consisting of three screen shots as follows:

1. What one gets when one builds the app and runs the demo. The application frame renders blank!
2. Making some adjustments so as not to make use of GTK, which I was doing previously, specified in U++ issue 1481.
3. Rebuilding and running the demo with GUI.NOGTK specified. The background gets rendered beneath the GL Window.


Unlike before, (msg 48505) no heap errors were encountered when running the U++ demo! Unfortunately, the fix (issue 1481) targeted for the next major release of U++ (2018.2) no longer can be applied since, "hasdhctrl" is no longer defined.



Peter