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Dependencies

Formats​

The [dependencies] section supports three formats:

String (registry)​

[dependencies]
fmt = "10.1.1"
spdlog = "1.12"
catch2 = "3.4.0"

The version string is used as-is for registry lookup.

Table (git)​

[dependencies]
dcr-math = { git = "https://github.com/dexoron/dcr-math-lib.git", tag = "v0.1.0" }

Fields: git, branch, tag, rev, mode, include, lib, libs.

Table (path)​

[dependencies]
mylib = { path = "../mylib" }

For a prebuilt external library, specify its layout explicitly. The three arrays are paths relative to the dependency root (include, lib) and linker names (libs):

[dependencies]
dcr-math = { path = "../deps/dcr-math", include = ["include"], lib = ["lib"], libs = ["dcr-math"] }

Registry​

DCR uses a package registry for dependency lookup by name.

# ~/.dcr/config.toml
[registry.default]
url = "https://index.dcr.dexoron.tech"
priority = 1

Registry priority: order in config.toml. The DCR_INDEX_PATH variable overrides the path to index.json.

Git dependencies​

Git dependencies are cloned into ~/.dcr/git/; their exact checked-out commit is written to dcr.lock.

Both Git and path dependencies have two modes:

  • DCR package: the source has dcr.toml. DCR builds it before the consumer and uses the package name from its manifest for linking.
  • Prebuilt library: it provides existing headers and binaries through include, lib, and libs. DCR passes them to the compiler/linker without building the dependency.

The mode is normally detected automatically. Use mode = "build" or mode = "prebuild" when a source contains both a manifest and prebuilt artifacts and you need to choose explicitly.

dcr-math-lib publishes both forms. Select its prebuilt library explicitly:

[dependencies]
dcr-math = { git = "https://github.com/dexoron/dcr-math-lib.git", tag = "v0.1.0", mode = "prebuild", include = ["include"], lib = ["lib"], libs = ["dcr-math"] }

DCR supports specifying branch/tag/rev for git sources:

  • branch — switch to a branch
  • tag — switch to a tag
  • rev — switch to a specific commit
  • features — feature flags (parsed, but does not affect build)

Path dependencies​

Local paths may point at a DCR package or a prebuilt external library. A path DCR package is built before its consumer, including its own path/git dependencies. DCR detects dependency cycles. A prebuilt library is never built by DCR; it is linked from the directories declared in its dependency entry.

[dependencies]
mylib = { path = "/abs/path/to/lib" }
mylib = { path = "../relative/path" }

For DCR packages, the package name from dcr.toml is used for linking (so the dependency key may differ from the library name). Header resolution includes the packaged target/include directory and link search includes target/lib.

Buildable DCR library:

dcr-math-lib/
├── dcr.toml
└── src/
    ├── dcr_math.c
    └── dcr_math.h

Prebuilt library:

dcr-math-lib/
├── include/
│   └── dcr_math.h
└── lib/
    └── libdcr-math.a       # or .so / .lib

libs contains linker names without the lib prefix and file extension: use ["dcr-math"] for libdcr-math.a.

If one repository contains both forms, keep the prebuilt files in include/ and lib/ and select the mode explicitly:

[dependencies]
dcr-math = { git = "https://github.com/dexoron/dcr-math-lib.git", tag = "v0.1.0", mode = "prebuild", include = ["include"], lib = ["lib"], libs = ["dcr-math"] }

For a local copy, replace git with path = "../dcr-math-lib". In prebuild mode DCR does not run the dependency build, even when dcr.toml is present.

dcr.lock​

Dependency lock file. Contains package names and sources.

Created during dcr build for resolved registry, path, and Git dependencies. Not updated during dcr add — only on the next dcr build.

Resolution process​

  1. Resolve dependency sources (registry → git → path)
  2. Fetch git dependencies into ~/.dcr/git/ and check out the requested ref
  3. Build DCR package dependencies recursively
  4. Collect include_dirs, lib_dirs, libs for the compiler