problem:
* vfork has been removed from POSIX [0].
* clang-tidy flags the `strerror` and `eerror` call inside the vfork-ed
child as undefined behavior.
solution: use posix_spawnp, which is serves similar purpose and is
specified in posix. and as an added bonus, it's also easier to use and
less lines of code.
[0]: https://www.man7.org/linux/man-pages/man2/vfork.2.html#CONFORMING_TO
`seed_dir` gets allocated via xstrdup but never gets freed - which
clang-tidy flags as a memory leak.
instead of free-ing the allocation, just don't allocate to begin with
since there's no need for it.
also bump the copyright year.
this was reported by codeql's scan as a TOCTOU bug. while that's true in
theory, i don't believe it would've had any practical effect.
a better justification for this change might be the fact that it
upgrades from `utime` (which is depreciated by POSIX [0]) to `futimens`.
[0]: https://www.man7.org/linux/man-pages/man3/utime.3p.html#FUTURE_DIRECTIONS
malloc (called by xasprintf) is not async-signal-safe. beside, the
string here is constant, so there's no need to malloc it all.
eerrorx isn't async-signal-safe either (due to calling fprintf and exit)
but consequence of them are _typically_ not as grave as calling malloc
while it's internal state is inconsistent.
Bug: https://github.com/OpenRC/openrc/issues/589
NRK
