Hi ! this is blocking migration of libglvnd from 1.1.0-1 to 1.3.0-5, which in turn is blocking migration of qtbase-opensource-src from 5.12.5+dfsg-2 to 5.12.5+dfsg-5, which in turn is blocking doxygen (that's where this hits me !).
I have verified that libgl-dev 1.3.0-5 indeed breaks the 3depict build. It seems that the d/control file should be fixed similarly to this commit: https://salsa.debian.org/xorg-team/lib/libglvnd/commit/cdfd0513bcf80c120332211cc89da1ff0be1204d Actually upstream README says: "GL/ contains code for libGL. This is a wrapper around libGLdispatch and libGLX" so libgl-dev could be made to depend on libglvnd-dev and libglx-dev (latter will pull in libx11-dev), exactly as libgl1 depends on libglvnd0 and libglx0. Thanks, Paolo