The dup2('refresh') added for O_CLOEXEC/stale-fd correctness fails for some
exec'd children (observed: a uid-dropped, namespace-restricted login shell)
and propagated as a spawn ENOENT. Fall back to the plain lseek when the
refresh syscall errors so process startup always succeeds; the refresh
still applies wherever the kernel permits it. Prevents any spawn
regression while the refresh path is stabilized for restricted children.
Red Bear OS
01d229fa5c