This is a nicer separation of concerns --- `DerivationBuilder` just
mounts the extra paths you tell it too, and the outside world is
responsible for making sure those extra paths make sense.
Since the closure only depends on global settings, and not
per-derivation information, we also have the option of moving this up
further and caching it across all local builds. (I only just realized
this after having done this refactor. I am not doing that change at this
time, however.)
Now, `DerivationBuilder` only concerns itself with `finalEnv` and
`extraFiles`, in straightforward unconditional code. All the fancy
desugaring logic is consolidated in `DerivationBuildingGoal`.
We should better share the pulled-out logic with `nix-shell`/`nix
develop`, which would fill in some missing features, arguably fixing
bugs.
I think this is a better separation of concerns. `DerivationBuilder`
doesn't need to to the final, query-heavy details about how these things
are constructed. It just operates on the level of "simple, stupid" files
and environment variables.
As much as I prefer rewriting the parsed rather than unparsed JSON for
elegance, this gets in the way of the separation of concerns that I am
trying to do.
As a practical matter, any rewriting that this did will also be done by
the second round of rewriting that remains below, so removing this code
should have no effect.
This is needed to rearrange include order, but I also think it is a good
thing anyways, as we seek to reduce the use of global settings variables
over time.
This avoids problems with older versions of Nix that don't put the
caches in WAL mode. That's generally not a problem, until you do something like
nix build --print-out-paths ... | cachix
which deadlocks because cachix tries to switch the caches to truncate
mode, which requires exclusive access. But the first process cannot
make progress because the cachix process isn't reading from the pipe.
With "truncate" mode, if we try to write to the database while another
process has an active write transaction, we'll block until the other
transaction finishes. This is a problem for the evaluation cache in
particular, since it uses long-running transactions.
WAL mode does not have this issue: it just returns "busy" right away,
so Nix will print
error (ignored): SQLite database '/home/eelco/.cache/nix/eval-cache-v5/...' is busy
and stop trying to write to the evaluation cache. (This was the
intended/original behaviour, see AttrDb::doSQLite().)
This systematizes the way our s3:// URLs are parsed in filetransfer.cc.
Yoinked out and refactored out of [1].
[1]: https://github.com/NixOS/nix/pull/13752
Co-authored-by: Bernardo Meurer Costa <beme@anthropic.com>
Compilers in nixpkgs have caught up and major distros
should also have recent enough compilers. It would be
nice to have newer features like more full featured
ranges and deducing this.
About time we upgraded our nixpkgs flake input. Ideally
we'd have automation to do this.
Flake lock file updates:
• Updated input 'nixpkgs':
'github:NixOS/nixpkgs/adaa24fbf46737f3f1b5497bf64bae750f82942e?narHash=sha256-qhFMmDkeJX9KJwr5H32f1r7Prs7XbQWtO0h3V0a0rFY%3D' (2025-05-13)
→ 'github:NixOS/nixpkgs/cd32a774ac52caaa03bcfc9e7591ac8c18617ced?narHash=sha256-VtMQg02B3kt1oejwwrGn50U9Xbjgzfbb5TV5Wtx8dKI%3D' (2025-08-17)
This caused RemoteStore::queryPathInfoUncached() to mark the
connection as invalid (see
RemoteStore::ConnectionHandle::~ConnectionHandle()), causing it to
disconnect and reconnect after every lookup of an invalid path. This
caused huge slowdowns in conjunction with
19f89eb684 and lazy-trees.
Period '.' is a special branch name in the gitsubmodule file which
represents the branch of the parent repository [1].
We add support for this by registering the ref of the InputAccessor to
be that of the parent input if '.' is encountered.
Fixes#13215
[1]: man gitmodules
lowdown >= 1.4.0 supports LOWDOWN_TERM_NORELLINK to render
absolute urls. This is useful, since we want to keep links to
web resources and such intact.
Fix description of `NIX_CONF_DIR`. It currently say that it defaults to `prefix/etc/nix`, which would mean `/nix/etc/nix` on default installations, and contradicts the description in `conf-file-prefix.md`.
This fix makes the description of `NIX_CONF_DIR` consistent with `conf-file-prefix.md`, assuming that the latter is correct.
