colcon-package-information

Common errors

• colcon: error: argument {build,test,install,package,help}: invalid choice: 'info' (choose from 'build', 'test', 'install', 'package', 'help')

  cause The `colcon info` verb is not recognized by `colcon`. This typically happens if `colcon-package-information` is not installed, or if `colcon-core` (its primary dependency) is missing or not discoverable by your Python environment.
  fix Ensure both `colcon-core` and `colcon-package-information` are installed in the active Python environment: `pip install colcon-core colcon-package-information`. Verify `colcon` is in your system's `PATH`.

• ModuleNotFoundError: No module named 'colcon_package_information'

  cause Attempting to import `colcon_package_information` directly as a regular Python library for end-user functionality. While the package *can* be imported, its primary purpose is as a `colcon` command-line extension, not a library for direct function calls.
  fix Instead of importing and calling functions, use the `colcon` command-line tool. For example, run `colcon info` in your terminal. If you need to interact with its output from Python, use `subprocess.run(['colcon', 'info'], capture_output=True)` and parse the result.

Warnings

• gotcha This package is a `colcon` extension and provides a new `colcon` verb (`info`). Its functionality is primarily accessed via the `colcon` command-line interface (e.g., `colcon info`), not by importing Python modules and calling functions directly within Python scripts for end-user tasks.
  Fix: Always invoke `colcon-package-information` via the `colcon` executable on the command line. For programmatic access to its *output*, consider using Python's `subprocess` module to run `colcon info` and parse its stdout.
• gotcha `colcon-package-information` requires `colcon-core` to be installed and available in the environment for the `colcon info` verb to be discovered and function correctly. Installing `colcon-package-information` alone without `colcon-core` will not expose the `info` verb.
  Fix: Ensure `colcon-core` is installed via `pip install colcon-core` alongside `colcon-package-information`.

Install

• pip install colcon-package-information Install colcon-package-information

Imports

• InfoVerb

  from colcon_package_information.verb.info import InfoVerb

  This library is primarily a `colcon` command-line extension; direct programmatic import of its internal components like `InfoVerb` is typically not done by end-users. Its functionality is accessed via the `colcon info` command.

Quickstart

This quickstart demonstrates how to install and use `colcon-package-information` via the `colcon` command-line interface. It creates a temporary `colcon` workspace with a dummy package, then executes `colcon info` to display the package's metadata. This highlights the primary interaction model, which is through the `colcon` CLI, not direct Python imports.

import os
import shutil

# Ensure colcon-core and colcon-package-information are installed
os.system("pip install colcon-core colcon-package-information")

workspace_path = "my_colcon_workspace"
package_path = os.path.join(workspace_path, "src", "my_package")

# Create a dummy colcon workspace and a simple package
os.makedirs(package_path, exist_ok=True)

package_xml_content = """
<package format='3'>
  <name>my_package</name>
  <version>0.1.0</version>
  <description>A dummy package for colcon info demonstration.</description>
  <maintainer email='dev@example.com'>Developer</maintainer>
  <license>Apache-2.0</license>
</package>
"""

with open(os.path.join(package_path, "package.xml"), "w") as f:
    f.write(package_xml_content)

print(f"\nCreated dummy workspace at: {workspace_path}")
print(f"Created dummy package 'my_package' at: {package_path}")

# Navigate into the workspace for colcon to find it
original_cwd = os.getcwd()
os.chdir(workspace_path)

# Run the colcon info command
print("\n--- Running colcon info for 'my_package' ---")
os.system("colcon info --packages-select my_package")

print("\n--- Running colcon info for all packages (if more existed) ---")
os.system("colcon info")

# Clean up
os.chdir(original_cwd)
shutil.rmtree(workspace_path)
print(f"\nCleaned up dummy workspace: {workspace_path}")