Function codec_thread_override 

pub fn codec_thread_override(
    setting: Option<&OsStr>,
) -> Result<Option<usize>, String>

The worker budget setting names: None unset, a positive count up to 64 (clamped), or the setting itself as the error when it is anything else (0, a word), which leaves the default in force.

Errors

Returns the setting, lossily as text, when it is not a positive count.