Comment # 5 on bug 69670 from Eugene

I am not sure how to confirm it. I tried launching:

LIBGL_ALWAYS_SOFTWARE=1 kwin --replace > kwin_stdout_LIBGL_ALWAYS_SOFTWARE.txt
2> kwin_stderr_LIBGL_ALWAYS_SOFTWARE.txt

and it disabled desktop effects; then I tried to switch to OpenGL 3.1 + Raster
and Kwin crashed displaying 'report bug assignment'  window and then was
restarted automatically without effects. I could not enable effect anyhow.

kwin_stdout_LIBGL_ALWAYS_SOFTWARE.txt was empty.