Whenever a file conflict happens during "nix profile install" an error
is shown that was previously thrown inside builtins.buildEnv.
We catch BuildProfileConflictError here so that we can provide the user
with more useful instructions on what to do next.
Most notably, we give the user concrete commands to use with all
parameters already filled in. This avoids the need for the user to look
up these commands in manual pages.
It is independent of SourceExprCommand, which is about parsing
installables, except for the fact that parsing installables is one of
the many things influenced by read-only mode.
Per the old FIXME, this flag was on too many commands, and mostly
ignored. Now it is just on the commands where it actually has an effect.
Per https://github.com/NixOS/nix/issues/7261, I would still like to get
rid of it entirely, but that is a separate project. This change should
be good with or without doing that.
`nix app` had something called `InstallableDerivedPath` which is
actually the same thing. We go with the later's name because it has
become more correct.
I originally did this change (more hurriedly) as part of #6225 --- a
mini store-only Nix and a full Nix need to share this code. In the first
RFC meeting for https://github.com/NixOS/rfcs/pull/134 we discussed how
some splitting of the massive `installables.cc` could begin prior, as
that is a good thing anyways. (@edolstra's words, not mine!) This would
be one such PR.
These settings are not needed for libstore at all, they are just used by
the nix daemon *command* for authorization on unix domain sockets. My
moving them to a new configuration struct just in that file, we avoid
them leaking anywhere else.
Also, it is good to break up the mammoth `Settings` struct in general.
Issue #5638 tracks this.
The message is not changed because I do not want to regress in
convenience to the user. Just saying "this connection is not trusted"
doesn't tell them out to fix the issue. The ideal thing to do would be
to somehow parameterize `processCommand` on how the error should be
displayed, so different sorts of connections can display different
information to the user based on how authentication is performed for the
connection in question. This, however, is a good bit more work, so it is
left for the future.
This came up with me thinking about the tcp:// store (#5265). The larger
project is not TCP *per se*, but the idea that it should be possible for
something else to manage access control to services like the Nix Daemon,
and those services simply trust or trust the incoming connection as they
are told. This is a more capability-oriented way of thinking about trust
than "every server implements its own auth separately" as we are used to today.
Its very great that libstore itself already implements just this model,
and so via this refactor I basically want to "enshrine" that so it
continues to be the case.
For frameworks it's important that structures are as lazy as possible
to prevent infinite recursions, performance issues and errors that
aren't related to the thing to evaluate. As a consequence, they have
to emit more attributes than strictly (sic) necessary.
However, these attributes with empty values are not useful to the user
so we omit them.
No other getDefaultFlakeAttrPaths implementation has this trailing dot,
and the dot can show up in error messages like:
error: flake '...' does not provide attribute 'packages.x86_64-linux.', ...
Avoid needless work and throwing away invariants.
These conversions date back to when `StorePath` was in Rust and there
were issues with it missing utility methods.
Rather than using `/nix/var/nix/{profiles,gcroots}/per-user/`, put the user
profiles and gcroots under `$XDG_DATA_DIR/nix/{profiles,gcroots}`.
This means that the daemon no longer needs to manage these paths itself
(they are fully handled client-side). In particular, it doesn’t have to
`chown` them anymore (removing one need for root).
This does change the layout of the gc-roots created by nix-env, and is
likely to break some stuff, so I’m not sure how to properly handle that.
Instead of needing to run `nix show-config --json | jq -r
'."warn-dirty".value'` to view the value of `warn-dirty`, you can now
run `nix show-config warn-dirty`.
`DerivedPath::Built` and `DerivationGoal` were previously using a
regular set with the convention that the empty set means all outputs.
But it is easy to forget about this rule when processing those sets.
Using `OutputSpec` forces us to get it right.
Prior to this change, we had a bunch of ad-hoc string manipulation code
scattered around. This made it hard to figure out what data model for
string contexts is.
Now, we still store string contexts most of the time as encoded strings
--- I was wary of the performance implications of changing that --- but
whenever we parse them we do so only through the
`NixStringContextElem::parse` method, which handles all cases. This
creates a data type that is very similar to `DerivedPath` but:
- Represents the funky `=<drvpath>` case as properly distinct from the
others.
- Only encodes a single output, no wildcards and no set, for the
"built" case.
(I would like to deprecate `=<path>`, after which we are in spitting
distance of `DerivedPath` and could maybe get away with fewer types, but
that is another topic for another day.)
This has the same goal as b13fd4c58e81b2b2b0d72caa5ce80de861622610,but
achieves it in a different way in order to not break
`nix why-depends --derivation`.
This makes 'nix develop' set the Linux personality in the same way
that the actual build does, allowing a command like 'nix develop
nix#devShells.i686-linux.default' on x86_64-linux to work correctly.
why-depends assumed that we knew the output path of the second argument.
For CA derivations, we might not know until it's built. One way to solve
this would be to build the second installable to get the output path.
In this case we don't need to, though. If the first installable (A)
depends on the second (B), then getting the store path of A will
necessitate having the store path B. The contrapositive is, if the store
path of B is not known (i.e. it's a CA derivation which hasn't been
built), then A does not depend on B.
after discussing this with multiple people, I'm convinced that "build
task" is more precise: a derivation is not an action, but inert until it
is built. also it's easier to pronounce.
proposal: use "build task" for the generic concept "description of how
to derive new files from the contents of existing files". then it will
be easier to distinguish what we mean by "derivation" (a specific data
structure and Nix language value type) and "store derivation" (a
serialisation of a derivation into a file in the Nix store).
I just had a colleague get confused by the previous phrase for good
reason. "valid" sounds like an *objective* criterion, e.g. and *invalid
signature* would be one that would be trusted by no one, e.g. because it
misformatted or something.
What is actually going is that there might be a signature which is
perfectly valid to *someone else*, but not to the user, because they
don't trust the corresponding public key. This is a *subjective*
criterion, because it depends on the arbitrary and personal choice of
which public keys to trust.
I therefore think "trustworthy" is a better adjective to use. Whether
something is worthy of trust is clearly subjective, and then "trust"
within that word nicely evokes `trusted-public-keys` and friends.
