Trouble with installing uv subpackages within monorepo

Context

I'm setting up a Python monorepo using uv for dependency management. When I run uv sync in the root directory, only the root package's dependencies are installed - none of the subpackages' dependencies are being installed.

I'm building a data platform monorepo using Python 3.12 and uv for dependency management. The project has several components:

• A core library (engine-core)
• An orchestrator for data pipelines (orchestrator)
• A dbt project for data modeling (dbt_forge)

Project Structure

Here's the (simplified) project structure :

custom-data-forge/
├── pyproject.toml
└── packages/
   ├── engine-core/ # Python library with importable modules
   │ └── pyproject.toml
   ├── orchestrator/ # Airflow DAGs and pipeline code
   │ └── pyproject.toml
   └── modeling/
     └── dbt_forge/ # dbt models and ClickHouse transformations
       └── pyproject.toml

Configuration

Root pyproject.toml:

[project]
name = "custom-data-forge"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = ["pandas", "sqlalchemy", "tabulate"]

[tool.uv.workspace]
members = [
    "packages/engine-core",
    "packages/orchestrator",
    "packages/modeling/dbt_forge",
]

Subpackage pyproject.toml files:

# packages/engine-core/pyproject.toml
[project]
name = "engine-core"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = ["dbt-core", "dbt-clickhouse"]

# packages/orchestrator/pyproject.toml
[project]
name = "orchestrator"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = ["engine-core", "apache-airflow"]

# packages/modeling/dbt_forge/pyproject.toml
[project]
name = "dbt_forge"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = ["dbt-core", "dbt-clickhouse"]

The Problem

When I run uv sync in the root directory:

• Only the root package's dependencies (pandas, sqlalchemy, etc.) are installed
• None of the subpackages' dependencies are installed (dbt-core, dbt-clickhouse, apache-airflow)

What I've Tried

1. Added [tool.uv] package = true to the subpackages' pyproject.toml files
2. Verified the workspace configuration in the root pyproject.toml
3. Made sure all [build-system] sections are properly configured
4. Deleted uv.lock and tried again

Questions

1. Is this the expected behavior for uv workspaces? Shouldn't uv sync install dependencies from all workspace members?
2. What's the correct way to configure uv to install dependencies from subpackages?
3. Do I need to make the subpackages "real" Python packages (with __init__.py files) for uv to recognize them?

Environment

• Python 3.12
• uv 0.6.16
• Linux 5.15.167.4-microsoft-standard-WSL2

There are two ways to solve this :

• Include subpackages as dependencies in your root pyproject.toml

  dependencies = ["engine-core", "orchestrator", "dbt-forge", "tabulate"]
  
  
  [tool.uv.workspace]
  # Workspace members (local packages)
  members = [
      "packages/engine-core",
      "packages/orchestrator",
      "packages/dbt-forge",
  ]
  
  [tool.uv.sources]
  # Map local package names to workspace members
  engine-core = { workspace = true }
  orchestrator = { workspace = true }
  dbt-forge = { workspace = true }
  

• Use the flag uv sync --all-packages