So this goes into tracker: I have isolated the problem to the following change in the nx-libs Makefile between 3.5.0.21 and 3.5.0.22, which persists through HEAD: --- nx-libs-3.5.0.21/Makefile 2014-06-14 12:45:27.000000000 -0400 +++ nx-libs-HEAD/Makefile 2014-06-12 16:31:48.000000000 -0400 @@ -3,6 +3,7 @@ INSTALL_DIR=install -d -m 755 INSTALL_FILE=install -m 644 INSTALL_PROGRAM=install -m 755 +INSTALL_SYMLINK=ln -s -f COPY_SYMLINK=cp -a RM_FILE=rm -f RM_DIR=rmdir -p --ignore-fail-on-non-empty @@ -114,6 +115,13 @@ "$$(string_rep "$$dirname" nx-X11/.build-exports/include "$(DESTDIR)$(PREFIX)/include/nx")"/ || true; \ done; \ + # Provide means for Xinerama support in NX/X2Go sessions. This + # This also requires two post-install symlinks: + # (DESTDIR)$(NXLIBDIR)/X11/Xinerama/libNX_X11.so.6 -> /usr//libX11.so.6 + # (DESTDIR)$(NXLIBDIR)/X11/Xinerama/libNX_Xext.so.6 -> /usr//libXext.so.6 + $(INSTALL_DIR) $(DESTDIR)$(NXLIBDIR)/X11/Xinerama + $(INSTALL_SYMLINK) ../libNX_Xinerama.so.1 $(DESTDIR)$(NXLIBDIR)/X11/Xinerama/libXinerama.so.1 + $(INSTALL_DIR) $(DESTDIR)$(PREFIX)/include/nx/X11/bitmaps $(INSTALL_FILE) nx-X11/.build-exports/include/X11/bitmaps/* \ $(DESTDIR)$(PREFIX)/include/nx/X11/bitmaps/ Commenting out the Xinerama lines and rebuilding results in a clean run of my (and your) python scripts as well as VLC player. I have attached a diff (excepting whitespace differences (diff -ub) of my system's Xinerama.c (xorg's libXinerama 1.1.3) and the one provided in x2go's source (based on XFree86). -- Sven Willenberger United Pay Systems International http://www.upsicorp.com