Whenever i add code to squeekboard it tricks me into the most trivial errors by e.g. not warning or burrying the warning under other warnings so
- cleanup C warnings
- enable --Werror in C
- enable the rust warnings i grasp (it leaves
#[warn(deprecated)]where i'm not sure how this is handled properly with different rust versions) - fixes a leak
- modernizes some GObject
- enables more compiler warnings