They lazy table generation these conversions use causes
babl to overestimate their cost while also overestimating
their accuracy.
I used "#if 0" rather than disabling the library because I
want to ensure the conversion gets removed without people
needing to do rm lib/babl-0.1/*
int
init (void)
{
+#if 0
const Babl *rgbaF = babl_format_new (
babl_model ("RGBA"),
babl_type ("float"),
o (rgb8, rgbA8);
o (rgba8, rgb8);
o (rgbaF, rgbA8);
+#endif
return 0;
}