If you find a bug in Factor, please report it to the Bug tracker after making sure its not a known problem listed below.

Known problems

Sometimes, bugs in compilers and graphics drivers cause problems for Factor. Before reporting a bug in Factor, consult the below list; all you might need to do is update your operating system.

GCC bugs

• Some builds of GCC 4.3 have problems compiling Factor on x86 and x86.64. Change the CFLAGS in the Makefile from -O3 to -O1 to work around the issue.
• GCC 3.3 and earlier cannot be used to compile Factor on x86 due to bugs in the register allocator.

These two issues don't affect most Linux distros which ship stable and up-to-date GCC versions. As a last resort, you can always compile a recent GCC from source.

Video driver bugs

Linux

Intel driver texture corruption bug

Version 2.4 of the Intel drivers have a texture corruption issue if more than one GL application is running at the same time, or if one GL application opens more than one window. If you experience garbled text in the Factor UI workspace, then you need to update to version 2.5 of the Intel drivers.

If you are using Ubuntu, just follow the directions at https://launchpad.net/~intel-gfx-testing/+archive.

Compiz black window bug

If you are using Compiz, you might encounter the infamous "flashing black window" problem. This is a bug in Compiz and any OpenGL application is affected; one workaround is to enable indirect rendering.

To enable indirect rendering, edit /etc/xdg/compiz/compiz-manager and add the following line:

INDIRECT="yes"

(From http://farfewertoes.com/stories/2008-07-30-ubuntu-tip-enable-indirect-rendering/)

ATI GART crash bug

You might get this error when running the Factor UI on Ubuntu Linux 8.04, after which the UI will crash:

*********************************WARN_ONCE*********************************
File r300_mem.c function r300_mem_alloc line 225
Ran out of GART memory (for 1048576)!
Please consider adjusting GARTSize option.
***************************************************************************
Error: Could not get dma buffer... exiting

The problem is caused by a bug in the Ubuntu X11 configuration tool; any OpenGL program will be affected and there is nothing Factor can do about it. A fix is discussed at https://bugs.launchpad.net/ubuntu/+source/stellarium/+bug/200173.

Windows

If you are running Windows with an older driver version and an Intel 9xx graphics adapter, you may notice rendering artifacts in the Factor UI. This is due to bugs in Intel's OpenGL implementation, and newer driver versions address this issue.

nano_count non-monotonicity errors

nano_count uses system calls which are defined to be monotonic. On some VMs and elsewhere, the system call fails to be so, time goes backwards, and nano_count raises an error.