pub fn effective_environment(
declared: &BTreeMap<String, String>,
) -> BTreeMap<String, String>Expand description
The complete environment a differential run executes in.
Starts from the pass-through list — PATH, HOME, TMPDIR, taken from
this process when present, because subprocess commands are unrunnable
without them — and lets the command file’s declared env override. The
result is exactly what crate::differential::run_merged_vs_parents
should be given, and exactly what environment_hash attests.