Every Rust derivation used to emit a warning like the following:
```
setting SOURCE_DATE_EPOCH to timestamp 1490877042 of file cargo-6e0c18c/Cargo.lock
warning: file cargo-6e0c18c/Cargo.lock may be generated; SOURCE_DATE_EPOCH may be non-deterministic
```
The reason is that the dependencies are copied without preserving
timestamps. Changing the build script to timestamp-preserving copy
removes the warning.
The varnish tools (varnishstat, varnishlog, ...) tried to load the VSM
file from a spurious var directory in the Nix store. Fix the default so
the tools "just work" when also keeping services.varnish.stateDir at the
default.
Notes:
- The tools use $localstatedir/$HOSTNAME so I've adapted the default for
stateDir as well to contain hostName.
- Added postStop action to remove the localstatedir. There is no point
in keeping it around when varnish does not run, as it regenerates it
on startup anyway.
Fixes#7495
We currently only allow upstream's default of "reboot.target" due to the
way the symlinks are initialized. I made this configurable similar to the
default unit.
Switch off HAVE_SAVED_UIDS since it activates a code path for temporary
privilege dropping which does not work on NixOS.
Vixie-cron's sources ship with two implementations. Unfortunately, the
one activated by HAVE_SAVED_UIDS (using setuid()) does not work on
NixOS. Saved UIDs work only if the program which is using them has the
setuid bit set on its own executable, not if called from a setuid
wrapper (as we do it in NixOS). The other implementation (using
setreuid()) works without problems.
Quote from
<http://stackoverflow.com/questions/8499296/realuid-saved-uid-effective-uid-whats-going-on>:
If you're euid is root and you change the uid, the privileges gets
dropped permanently.If effective user id is not root then saved user
id is never touched and you can regain the root privilege back
anytime you want in your program.
Also extend the default PATH with NixOS-specific bin directories as
vixie-cron's default is not really usable on NixOS.
Re #16518Closes#16522
Christian Kauhaus