We're seeing the same error as a few other groups with our OpenGL X11 software. If a user opens, closes and then reopens a window, the program crashes with the following error:
xp_import_surface: assertion failed: s == NULL
error: xp_import_surface returned: 2
xp_destroy_surface: assertion failed: s != NULL
xp_destroy_surface error: 3
This problem is relatively recent and specific to MacOS Sierra 10.12.4-6. Previous Sierra 10.12.3 and prior versions of MacOS and other Linux distributions do not have this issue.
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