Enemy Territory Quake Wars saves 32 bit TGA screenshots, and the alpha value of
the pixels is set to 0x00 instead of 0xFF. Team Fortress 2 saves 24 bit TGA
screenshots (before converting to jpeg), and the whole thing is black.

I also tried Doom3, Prey, Quakespasm, Nexuiz, UT2004, Half-Life 1, and Garry's
Mod but those are not affected.

This is a regression, but I couldn't find an old version of mesa that worked. I
went back as far as to 5ffa28df4e4cc224 (the first one that compiles with bison
3), and libdrm 2.4.44, but couldn't find a version that was good. When
screenshots were good, I had mesa 9.2.2 installed, and I used 10.0-dev for
running games. Now I have 10.1 installed. Maybe I need to roll back the
installed libs?