E.g. in a derivation attribute `foo = ./bar`, if ./bar is a symlink,
we should copy the symlink to the store, not its target. This restores
the behaviour of Nix <= 2.19.
"content-address*ed*" derivation is misleading because all derivations
are *themselves* content-addressed. What may or may not be
content-addressed is not derivation itself, but the *output* of the
derivation.
The outputs are not *part* of the derivation (for then the derivation
wouldn't be complete before we built it) but rather separate entities
produced by the derivation.
"content-adddress*ed*" is not correctly because it can only describe
what the derivation *is*, and that is not what we are trying to do.
"content-address*ing*" is correct because it describes what the
derivation *does* --- it produces content-addressed data.
This is a big step documenting the store layer on its own, separately from the evaluator (and `builtins.derivation`).
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
This uses the single-threaded C-based routines from libblake3.
This is not optimal performance-wise but should be a good starting point
for nix compatibility with BLAKE3 hashing until a more performant
implementation based on the multi-threaded BLAKE3 routines
(written in Rust) can be developed.
This allows a flake to specify that it needs Git submodules to be
enabled (or disabled, if we ever change the default) on the top-level
flake. This requires the input to be refetched, but since the first
fetch is lazy, this shouldn't be expensive.
Currently the only attribute allowed by `inputs.self` is `submodules`,
but more can be added in the future (e.g. a `lazy` attribute to opt in
to lazy tree behaviour).
Fixes#5312, #9842.
If we previously fetched by revision, the output of "git ls-remote"
won't start with the expected line like
ref: refs/heads/master HEAD
but will be something like
5c4410e3b9891c05ab40d723de78c6f0be45ad30 refs/heads/5c4410e3b9891c05ab40d723de78c6f0be45ad30
This then causes Nix to treat that revision as a refname, which then
leads to warnings like
warning: could not update cached head '5c4410e3b9891c05ab40d723de78c6f0be45ad30' for 'file:///tmp/repo'
This causes Git to create a local ref named refs/head/<rev>, e.g.
$ git -C ~/.cache/nix/gitv3/11irpim06vj4h6c0w8yls6kx4hvl0qd0gr1fvk47n76g6wf1s1vk ls-remote --symref .
5c4410e3b9891c05ab40d723de78c6f0be45ad30 refs/heads/5c4410e3b9891c05ab40d723de78c6f0be45ad30
7f6bde8a20de4cccc2256f088bc5af9dbe38881d refs/heads/7f6bde8a20de4cccc2256f088bc5af9dbe38881d
which confuses readHead(), leading to errors like
fatal: Refusing to point HEAD outside of refs/
warning: could not update cached head 'd275d93aa0bb8a004939b2f1e87f559f989453be' for 'file:///tmp/repo'
Git interprets them as part of the file name, so passing parameters
like 'rev' breaks. Only relevant for testing (when _NIX_FORCE_HTTP is
set) and local bare repos.
Fixes messages like 'copying /tmp/repo/tmp/repo to the store'. The
PosixSourceAccessor already sets the prefix. Setting the prefix twice
shouldn't be a problem, but GitRepoImpl::getAccessor() returns a
wrapped accessor so it's not actually idempotent.
The main improvement is that the new message gives an example of a path
that is referenced, which should make it easier to track down. While
there, I also clarified the wording, saying exactly why the paths in
question were illegal.
