We immediately use this in the JSON schemas for Derivation and Deriving
Path, but we cannot yet use it in Store Object Info because those paths
*do* include the store dir currently.
- Uses the more explicit `@ingroup` most of the time, to avoid problems
with nested groups, and to make group membership more explicit.
The division into headers is not great for documentation purposes,
so this helps.
- More attention for memory management details
- Various other improvements to doc comments
Per #7591, the `nix-store --gc --print-dead` command does not provide
any feedback about the amount of disk space that is used by dead store
paths. It looks like this has been the case since 7ab68961e (* Garbage
collector: added an option `--use-atime' to delete paths in...,
2008-09-17).
Update the nix-store documentation to remove the claim that this is
function that `nix-store --gc --print-dead` performs.
Implements comprehensive cycle detection that shows users exactly which
files create circular dependencies when a build fails. This dramatically
improves the developer experience when debugging dependency cycles.
Adds cycle detection to DependencyGraph using DFS with back-edge detection.
This will be used by the cycle detection feature for build errors.
Each cycle is represented as a path that starts and ends at the same node,
e.g., [A, B, C, A].
Adds buildStorePathGraphFromScan() to bridge the generic DependencyGraph
infrastructure with Nix's store path reference scanning. This enables
building annotated dependency graphs that track which files create which
dependencies.
## New API: buildStorePathGraphFromScan()
**Purpose**: Convert file-level scan results into a StorePath-level graph
**How it works**:
1. Calls scanForReferencesDeep() to find which files contain references
2. For each file that references another store path:
- Adds edge: rootStorePath → referencedStorePath
- Attaches FileListEdgeProperty with the file path
3. Returns DependencyGraph<StorePath, FileListEdgeProperty>
**Key benefit**: The graph carries file-level provenance. When you see
an edge A→B, you can query which files in A reference B. Essential for:
- why-depends output showing exact file locations
- Future: detailed cycle error messages
## API Changes
**scanForReferencesDeep() callback signature**:
```cpp
// Before: std::function<void(FileRefScanResult)>
// After: std::function<void(const FileRefScanResult &)>
```
Pass by const-ref to avoid copying large result structures.
## Usage Example
```cpp
auto graph = buildStorePathGraphFromScan(
*accessor,
CanonPath("/nix/store/abc-foo"),
storePathAbc,
candidateRefs
);
// Query file annotations
auto edgeProp = graph.getEdgeProperty(storePathAbc, storePathDef);
// edgeProp->files contains files that created this edge
```
## Implementation Details
- Uses DependencyGraph's edge properties feature
- FileListEdgeProperty defined in dependency-graph.hh
- Merges duplicate edges (multiple files → same path)
- Debug logging for discovered edges
- Zero overhead if file-level detail not needed
Introduces a reusable directed graph template built on Boost Graph Library
(BGL) to provide graph operations for store path dependency analysis. This
will be used by `nix why-depends` and future cycle detection.
Implement `uploadPart()` for uploading individual parts in S3 multipart
uploads:
- Constructs URL with `?partNumber=N&uploadId=ID` query parameters
- Uploads chunk data with `application/octet-stream` mime type
- Extracts and returns `ETag` from response
Add concurrency group configuration to the CI workflow to automatically
cancel outdated runs when a PR receives new commits or is force-pushed.
This prevents wasting CI resources on superseded code.
This is a good default (the methods that allow for an arbitrary choice
of source accessor are generally preferable both to implement and to
use). And it also pays its way by allowing us to delete *both* the
`DummyStore` and `LocalStore` implementations.
Introduces `scanForReferencesDeep` to provide per-file granularity when
scanning for store path references, enabling better diagnostics for
cycle detection and `nix why-depends --precise`.
Implement `abortMultipartUpload()` for cleaning up incomplete multipart
uploads on error:
- Constructs URL with `?uploadId=ID` query parameter
- Issues `DELETE` request to abort the multipart upload
