Bugs: OS and system issues

An update to the macos Sierra operating system means that ChIPS will fail when creating a new window after an existing window has been deleted (such as via calls to clear and delete_window or by closing the window via its close button). Calling a command in this situation results in messages like the following:

error: xp_import_surface returned: 2
xp_destroy_surface: assertion failed: s != NULL
xp_destroy_surface error: 3
xp_import_surface: assertion failed: s == NULL

Repeating the command will start a new ChIPS server instance in the background, and so allow plotting to continue.

Systems using OpenGL Mesa version 6.5.* may experience problems with chips crashing due to a bug in mesa. The problem can occur if chips has been running a while and windows have been created and destroyed. In most cases the problem will be exposed by chips smoke test 3 failing.

The only known workaround is to update to a later version of Mesa (at least 7.0.2). To check your version of mesa run:

unix% glxinfo | grep version

Systems using OpenGL Mesa version 6.5.* may also experience problems when the environment variable LIBGL_ALWAYS_INDIRECT is set or while remote logged into another machine and trying to run chips. Attempts to run chips under these circumstances has caused the xserver to crash. The problem has been observed on FC6 and FC7 machines. The problem no longer exists on FC8 machines running OpenGL Mesa version 7.0.3

Some ATI graphics cards produce the following warning:

libGL warning: 3D driver claims to not support visual 0x4b

This does not seem to have any effect on ChIPS.