# \#colcon

**URL:** https://discourse.openrobotics.org/tag/colcon/154.md

[Latest](https://discourse.openrobotics.org/latest.md) · [Categories](https://discourse.openrobotics.org/categories.md) · [Tags](https://discourse.openrobotics.org/tags.md)

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## [ \[GSoC 2026\]  Add Support for Mixin Composition in Colcon-Mixin — Progress Update](https://discourse.openrobotics.org/t/gsoc-2026-add-support-for-mixin-composition-in-colcon-mixin-progress-update/57408)

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**Author:** [@Pious](https://discourse.openrobotics.org/u/Pious)\
**Replies:** 1\
**Last updated:** [August 28, 2026, 10:17pm UTC](https://discourse.openrobotics.org/t/gsoc-2026-add-support-for-mixin-composition-in-colcon-mixin-progress-update/57408 "2026-08-28T22:17:32Z")

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Organization: OSRF Contributor: Innocent Pious (GitHub, LinkedIn) Mentors: Scott Logan (GitHub) and Kimberly McGuire (GitHub) GSoC project: Add Support for Mixin Composition in Colcon-Mixin Repository: colcon-mixin P…

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## [Uv on ROS 2: a field report on workspace-level virtual environments — five failure modes and minimal colcon/ament proposals](https://discourse.openrobotics.org/t/uv-on-ros-2-a-field-report-on-workspace-level-virtual-environments-five-failure-modes-and-minimal-colcon-ament-proposals/57111)

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**Author:** [@Decwest](https://discourse.openrobotics.org/u/Decwest)\
**Replies:** 16\
**Last updated:** [August 8, 2026, 10:47pm UTC](https://discourse.openrobotics.org/t/uv-on-ros-2-a-field-report-on-workspace-level-virtual-environments-five-failure-modes-and-minimal-colcon-ament-proposals/57111 "2026-08-08T22:47:22Z")

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TL;DR: A workspace-level uv-managed venv works on stock apt-installed ROS 2 — including a PyTorch+CUDA node — but we hit five reproducible failure modes on the way (verified on Jazzy; none of the mechanisms are Jazzy-spe…

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## [Status of Colcon building "standards-based" Python packages?](https://discourse.openrobotics.org/t/status-of-colcon-building-standards-based-python-packages/40578)

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**Author:** [@taughz](https://discourse.openrobotics.org/u/taughz)\
**Replies:** 14\
**Last updated:** [February 5, 2026, 10:19am UTC](https://discourse.openrobotics.org/t/status-of-colcon-building-standards-based-python-packages/40578 "2026-02-05T10:19:49Z")

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I have read the (now closed) topic: Call For Testing: Standards-based Python packaging with colcon. But it seems not much has happened in the linked repo since then. I have some co-workers who are asking why they need to…

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## [ROS Unsource script](https://discourse.openrobotics.org/t/ros-unsource-script/51310)

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**Author:** [@peci1](https://discourse.openrobotics.org/u/peci1)\
**Replies:** 3\
**Last updated:** [December 13, 2025, 12:32am UTC](https://discourse.openrobotics.org/t/ros-unsource-script/51310 "2025-12-13T00:32:07Z")

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Every little :turtle: knows how to source a ROS workspace, right? But what do they not tell you in the turorials? What they don’t want you to know??? How to unsource a workspace! I’ve put together this bash script that …

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## [Building a true release mode only](https://discourse.openrobotics.org/t/building-a-true-release-mode-only/50986)

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**Author:** [@Chuck\_Claunch](https://discourse.openrobotics.org/u/Chuck_Claunch)\
**Replies:** 6\
**Last updated:** [November 19, 2025, 9:14pm UTC](https://discourse.openrobotics.org/t/building-a-true-release-mode-only/50986 "2025-11-19T21:14:50Z")

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Hi, I’ve been working on building our software stack using only release mode and not building any packages which are test\_depend. The problem I’m having is colcon scoops up all the dependencies no matter how they’re mar…

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## [Introducing \`colcon\_gephi\` – Generate Rich Dependency Graphs Compatible With Graph Visualization Tools](https://discourse.openrobotics.org/t/introducing-colcon-gephi-generate-rich-dependency-graphs-compatible-with-graph-visualization-tools/50705)

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**Author:** [@maspe36](https://discourse.openrobotics.org/u/maspe36)\
**Replies:** 0\
**Last updated:** [October 26, 2025, 6:28pm UTC](https://discourse.openrobotics.org/t/introducing-colcon-gephi-generate-rich-dependency-graphs-compatible-with-graph-visualization-tools/50705 "2025-10-26T18:28:17Z")

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Have you ever run colcon graph --dot | dot -Tpng -o graph.png, waited a few minutes, and looked at unhelpful pngs? Have you ever asked thought-provoking questions like: What package is depended on the most? Who mainta…

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## [Meson Project Support](https://discourse.openrobotics.org/t/meson-project-support/44965)

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**Author:** [@christian](https://discourse.openrobotics.org/u/christian)\
**Replies:** 2\
**Last updated:** [July 2, 2025, 7:22pm UTC](https://discourse.openrobotics.org/t/meson-project-support/44965 "2025-07-02T19:22:26Z")

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Hi all, For a while now, I have worked on supporting the Meson build system in colcon and bloom. The colcon-meson extension was available for some time now, but the bloom support was only merged recently, and I think no…

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## [Colcon package-of](https://discourse.openrobotics.org/t/colcon-package-of/42113)

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**Author:** [@taughz](https://discourse.openrobotics.org/u/taughz)\
**Replies:** 1\
**Last updated:** [February 17, 2025, 8:17pm UTC](https://discourse.openrobotics.org/t/colcon-package-of/42113 "2025-02-17T20:17:22Z")

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Announcing a small Colcon extension: https://github.com/taughz/colcon-package-of pip install colcon-package-of Given a set of files, output a list of packages which contain those files. $ colcon package-of src/pkgX/…

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## [Build Systems, Package Management, and Nix](https://discourse.openrobotics.org/t/build-systems-package-management-and-nix/41488)

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**Author:** [@AngleSideAngle](https://discourse.openrobotics.org/u/AngleSideAngle)\
**Replies:** 51\
**Last updated:** [January 29, 2025, 2:37pm UTC](https://discourse.openrobotics.org/t/build-systems-package-management-and-nix/41488 "2025-01-29T14:37:49Z")

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Happy new year! As you may know, a new year means a new debate about ROS tooling… /j If your reaction to this title is, “not another beginner coming to this forum to voice their displeasure with bespoke build tools with…

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## [Leveraging ROS build infrastructure for non-ROS packages](https://discourse.openrobotics.org/t/leveraging-ros-build-infrastructure-for-non-ros-packages/40658)

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**Author:** [@RFRIEDM](https://discourse.openrobotics.org/u/RFRIEDM)\
**Replies:** 10\
**Last updated:** [December 6, 2024, 5:50pm UTC](https://discourse.openrobotics.org/t/leveraging-ros-build-infrastructure-for-non-ros-packages/40658 "2024-12-06T17:50:47Z")

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I had an interesting discussion with @peci1 over on the exiv2 github and we decided to move it here for some more opinions/recommendations because it illustrates a larger issue with the standard ROS 2 build tooling when …

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## [How to run multiple tests in parallel with colcon test?](https://discourse.openrobotics.org/t/how-to-run-multiple-tests-in-parallel-with-colcon-test/38675)

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**Author:** [@LastStarDust](https://discourse.openrobotics.org/u/LastStarDust)\
**Replies:** 1\
**Last updated:** [July 29, 2024, 1:34am UTC](https://discourse.openrobotics.org/t/how-to-run-multiple-tests-in-parallel-with-colcon-test/38675 "2024-07-29T01:34:36Z")

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I am currently engaged in a ROS2 project aimed at optimizing our testing processes by enabling concurrent execution of tests within a single package using colcon test. Initially, I attempted to utilize the --parallel-wo…

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## [Colcon in-container can now generate a Debian and runs on Linux, macOS and Windows](https://discourse.openrobotics.org/t/colcon-in-container-can-now-generate-a-debian-and-runs-on-linux-macos-and-windows/38101)

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**Author:** [@Guillaume\_beuzeboc](https://discourse.openrobotics.org/u/Guillaume_beuzeboc)\
**Replies:** 0\
**Last updated:** [June 6, 2024, 2:39pm UTC](https://discourse.openrobotics.org/t/colcon-in-container-can-now-generate-a-debian-and-runs-on-linux-macos-and-windows/38101 "2024-06-06T14:39:45Z")

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Hello everyone, A little less than a year ago, we announced the project: colcon in-container. At that time, it was a colcon verb extension to run colcon commands inside a fresh and isolated ROS environment. With this ex…

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## [ROS2 Build Tools & Systems](https://discourse.openrobotics.org/t/ros2-build-tools-systems/35173)

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**Author:** [@tele](https://discourse.openrobotics.org/u/tele)\
**Replies:** 88\
**Last updated:** [December 22, 2023, 9:22pm UTC](https://discourse.openrobotics.org/t/ros2-build-tools-systems/35173 "2023-12-22T21:22:06Z")

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I would like to contribute my 2cents on the ROS2 build tools and systems. Regardless of the ample and elaborate documentation on the build tools I, like many others fail to grasp the “why” of all this build tool/system (…

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## [Determine a base directory of a colcon workspace](https://discourse.openrobotics.org/t/determine-a-base-directory-of-a-colcon-workspace/34034)

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**Author:** [@furushchev](https://discourse.openrobotics.org/u/furushchev)\
**Replies:** 15\
**Last updated:** [October 12, 2023, 2:52pm UTC](https://discourse.openrobotics.org/t/determine-a-base-directory-of-a-colcon-workspace/34034 "2023-10-12T14:52:11Z")

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Hello all! I’m now trying to gradually migrate our system from ROS1 to ROS2 and getting used to the colcon and many other ROS2 tools. I realized that the colcon build command needs to be invoked on the specific directo…

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## [Colcon in-container, an extension to build and test ROS 2 inside a container](https://discourse.openrobotics.org/t/colcon-in-container-an-extension-to-build-and-test-ros-2-inside-a-container/33274)

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**Author:** [@Guillaume\_beuzeboc](https://discourse.openrobotics.org/u/Guillaume_beuzeboc)\
**Replies:** 5\
**Last updated:** [September 20, 2023, 11:35pm UTC](https://discourse.openrobotics.org/t/colcon-in-container-an-extension-to-build-and-test-ros-2-inside-a-container/33274 "2023-09-20T23:35:49Z")

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Hello everyone, Have you ever called rosdep on a ROS 2 package, only to realize that a dependency is missing when you try to build it? When developing a ROS 2 package or a ROS 2 workspace, one might rely on dependencies…

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## [Call For Testing: Standards-based Python packaging with colcon](https://discourse.openrobotics.org/t/call-for-testing-standards-based-python-packaging-with-colcon/32008)

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**Author:** [@cottsay](https://discourse.openrobotics.org/u/cottsay)\
**Replies:** 1\
**Last updated:** [June 19, 2023, 3:20pm UTC](https://discourse.openrobotics.org/t/call-for-testing-standards-based-python-packaging-with-colcon/32008 "2023-06-19T15:20:48Z")

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The Python Packaging Authority (PyPA) is in the process of deprecating the use of setup.py to build and install Python packages. This mechanism has been used for ament\_python packages since their inception, and is curren…

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## [Colcon extension for validating package dependencies](https://discourse.openrobotics.org/t/colcon-extension-for-validating-package-dependencies/31303)

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**Author:** [@Tacha-S](https://discourse.openrobotics.org/u/Tacha-S)\
**Replies:** 3\
**Last updated:** [June 1, 2023, 3:21pm UTC](https://discourse.openrobotics.org/t/colcon-extension-for-validating-package-dependencies/31303 "2023-06-01T15:21:36Z")

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I have published colcon-lint. It’s an extension of colcon-core. Similar to catkin-lint in ROS, it checks whether the dependencies of ROS2 packages are correctly described in the package.xml. It’s still a work in progres…

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## [Colcon Build from Any Directory and Need to Re-build for changes in Launch file](https://discourse.openrobotics.org/t/colcon-build-from-any-directory-and-need-to-re-build-for-changes-in-launch-file/17353)

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**Author:** [@pururastogi](https://discourse.openrobotics.org/u/pururastogi)\
**Replies:** 2\
**Last updated:** [November 16, 2020, 1:11pm UTC](https://discourse.openrobotics.org/t/colcon-build-from-any-directory-and-need-to-re-build-for-changes-in-launch-file/17353 "2020-11-16T13:11:12Z")

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New to ROS2 and Nav2 here. Currently my directory structure is like this : home\>nav2\_ws\>src\>navigation2. I need my build and install directory to be in nav2\_ws. For which currently I call colcon build --symlink-instal…

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## [ROS2 (cross) compilation: how to separate host tools, target binaries and graphics tools](https://discourse.openrobotics.org/t/ros2-cross-compilation-how-to-separate-host-tools-target-binaries-and-graphics-tools/14027)

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**Author:** [@razr](https://discourse.openrobotics.org/u/razr)\
**Replies:** 8\
**Last updated:** [May 16, 2020, 9:08pm UTC](https://discourse.openrobotics.org/t/ros2-cross-compilation-how-to-separate-host-tools-target-binaries-and-graphics-tools/14027 "2020-05-16T21:08:17Z")

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There are ~300 packages in the ROS2 distro. Some of them are host tools, like ament (no need to deploy on the target system), some are binaries installed on the target (libs etc.) and some are visualization tools like rv…