Function exec_in_dir 

pub fn exec_in_dir(dir: &Path, program: &str, args: &[String]) -> ExecStatus

Run program args… with the working directory set to dir.

The child inherits the parent’s stdio so its output streams to the user live (sequential execution keeps the streams from interleaving). Only the resolved exit status is captured and returned — a spawn failure (missing binary, permission denied) maps to ExecStatus::SpawnError rather than aborting the whole fan-out.