See this forum posting for a potential fix, if your using an ATI graphics card:
This is a fix for the bug where Cogs launches with the following output:
Shader compile log for data/effects/TextureBumpCubemap.fsh:
Fragment shader failed to compile with the following errors:
ERROR: 0:41: error(#132) Syntax error: ‘smooth’ parse error
ERROR: error(#273) 1 compilation errors. No code generated
Apparently the word “smooth” is reserved, but only on ATI cards in Linux. The fix is to modify the following file.
Just do a global replace of the word “smooth” with “Smooth”.
A huge thanks to Renee Marie Jones, who figured this one out
I wasn’t seeing that particular output on the console, and the screen was just blank/black and I could hear the music. But, this fix did work for me on Ubuntu Linux 10.10 (Maverick).