This fixes the warning
$ nix eval --store /tmp/nix --expr 'builtins.fetchTree { type = "git"; url = "https://github.com/DeterminateSystems/attic"; ref = "fixups-for-magic-nix-cache"; rev = "635753a2069d4b8228e846dc5c09ad361c75cd1a"; }'
warning: could not update mtime for file '/home/eelco/.cache/nix/gitv3/09788h9zgba5lbfkaa6ija2dvi004jwsqjf5ln21i2njs07cz766/refs/heads/fixups-for-magic-nix-cache': error: changing modification time of '"/home/eelco/.cache/nix/gitv3/09788h9zgba5lbfkaa6ija2dvi004jwsqjf5ln21i2njs07cz766/refs/heads/fixups-for-magic-nix-cache"': No such file or directory
When we're fetching by rev, that file doesn't necessarily exist, and we
don't care about it anyway.
this should make it more obvious how things are related to each other, and also
hopefully expose the historical context without having to say on every
corner that these details are accounting for legacy decisions.
Prior to this commit, the unit contained this line:
ExecStart=@share/nix-daemon nix-daemon --daemon
which caused systemd to complain:
Failed to restart nix-daemon.service: Unit nix-daemon.service has a bad unit file setting.
See system logs and 'systemctl status nix-daemon.service' for details.
and had this in the unit output:
Sep 03 13:34:59 scadrial systemd[1]: /etc/systemd/system/nix-daemon.service:10: Neither a valid executable name nor an absolute path: share/nix-daemon
Sep 03 13:34:59 scadrial systemd[1]: nix-daemon.service: Unit configuration has fatal error, unit will not be started.
(Notice how it's trying to execute `share/nix-daemon`, which is unlikely
to exist.)
Now with this commit, the path to the daemon binary is properly set:
ExecStart=@/nix/store/lcbx6d8gzznf3z3c8lsv9jy3j6c67x6r-nix-2.25.0pre20240903_dirty/bin/nix-daemon nix-daemon --daemon
The daemon process is now moved into a new sub-cgroup called nix-daemon when the
daemon starts. This is necessary to abide by the no-processes-in-inner-nodes
rule, because the service cgroup becomes an inner node when the child cgroups
for the build are created (see LocalDerivationGoal::startBuilder()).
See #9675
This broke in #11005. Any number of PathSubstitutionGoals would
be woken up by a single build slot becoming available. If there
are a lot of substitution goals active, this could lead to us
running out of file descriptors (especially on macOS where the
default limit is 256).
Meson-ify a few things, scripts, completions, etc. Should make our Meson
build complete except for docs.
Co-Authored-By: Qyriad <qyriad@qyriad.me>
Co-Authored-By: eldritch horrors <pennae@lix.systems>
