fn tryLockStderr( userdata: ?*anyopaque, terminal_mode: ?Io.Terminal.Mode, ) Io.Cancelable!?Io.LockedStderr
fn tryLockStderr( userdata: ?*anyopaque, terminal_mode: ?Io.Terminal.Mode, ) Io.Cancelable!?Io.LockedStderr { const ev: *Evented = @ptrCast(@alignCast(userdata)); const ev_io = ev.io(); if (!ev.stderr_mutex.tryLock()) return null; errdefer ev.stderr_mutex.unlock(ev_io); return try ev.initLockedStderr(terminal_mode); }