Dependency Resolution & Locking

Purpose

The dependency resolution and locking stage determines which dependencies are required for the project, resolves version constraints for package dependencies, builds a complete dependency tree, detects circular dependencies, and ensures reproducible builds through lock files.

When It Executes

This stage executes after Initialization & Configuration and is typically triggered by:

• The install_deps provider (dependency of compile)
• The lock provider (explicitly locking dependencies)
• Any command that requires dependencies to be resolved

The compile provider depends on the lock provider, which depends on install_deps.

Prerequisites

• State initialized with configuration loaded
• rebar.config parsed with dependencies list
• rebar.lock read (if exists) with locked versions
• Application discovery completed (for project apps)

Outputs

• Complete list of all dependencies (direct and transitive)
• Dependency tree with levels (depth from project root)
• Resolved versions for all package dependencies
• Updated rebar.lock file with locked versions
• Topologically sorted dependency list (compilation order)
• Updated state with:
  • all_deps: All resolved dependencies
  • deps_to_build: Dependencies that need compilation
  • lock: Current lock data