Function acquire_reserved_lock 

pub fn acquire_reserved_lock(
    context: &GitContext,
    cwd: &Path,
    layout: &InvocationLayout,
    environment: &[(OsString, OsString)],
    reservation: &LandingReservation,
) -> Result<OwnerLock, ReservationError>

What: Take the landing lock once no other transaction’s reservation stands in the way. Why: The reservation is checked again under the lock, so a reservation granted while this landing waited is honored.

In TS you’d write (pseudocode):

await using lock = await acquireReservedLandingLock({ gitPath, cwd, registryRoot, reservation });