Build agent's detection of the installed on the build agent machine Unity versions

Question

TeamCity Unity Support plugin is used for building Unity projects with TeamCity. Multiple versions of Unity are installed on the build agent machine.

How does the TeamCity build agent detect the installed versions of Unity on the build agent machine?

Answer

The build agent detects the Unity versions during startup. Records related to the Unity versions detection can be found in the <TeamCity build agent home>/logs/teamcity-agent.log file, during the agent startup. Example:

[2025-05-19 13:09:51,856] INFO - ty.detectors.UnityToolProvider - Locating Unity tools
[2025-05-19 13:09:51,918] INFO - ty.detectors.UnityDetectorBase - Looking in: C:\Windows\system32\config\systemprofile\AppData\Roaming\UnityHub
[2025-05-19 13:09:51,918] INFO - ty.detectors.UnityDetectorBase - C:\Windows\system32\config\systemprofile\AppData\Roaming\UnityHub does not exist.
[2025-05-19 13:09:51,918] INFO - ty.detectors.UnityDetectorBase - Looking in: C:\Program Files
[2025-05-19 13:09:51,918] INFO - ty.detectors.UnityDetectorBase - Found: C:\Program Files\Unity
[2025-05-19 13:09:51,918] INFO - ty.detectors.UnityDetectorBase - Found: C:\Program Files\Unity Hub
[2025-05-19 13:09:51,934] INFO - ty.detectors.UnityDetectorBase - Looking in: C:\Program Files\Unity\Hub\Editor
[2025-05-19 13:09:51,934] INFO - ty.detectors.UnityDetectorBase - Found: C:\Program Files\Unity\Hub\Editor\2022.3.17f1
[2025-05-19 13:09:51,981] INFO - ty.detectors.UnityToolProvider - Found Unity 2022.3.17 at C:\Program Files\Unity\Hub\Editor\2022.3.17f1
[2025-05-19 13:09:51,981] INFO - ty.detectors.UnityDetectorBase - Found: C:\Program Files\Unity\Hub\Editor\6000.0.29f1
[2025-05-19 13:09:51,997] INFO - ty.detectors.UnityToolProvider - Found Unity 6000.0.29 at C:\Program Files\Unity\Hub\Editor\6000.0.29f1
[2025-05-19 13:09:51,997] INFO - ty.detectors.UnityDetectorBase - Found: C:\Program Files\Unity\Hub\Editor\6000.1.1f1
[2025-05-19 13:09:52,139] INFO - ty.detectors.UnityToolProvider - Found Unity 6000.1.1 at C:\Program Files\Unity\Hub\Editor\6000.1.1f1
[2025-05-19 13:09:52,139] INFO - ty.detectors.UnityDetectorBase - Looking in: C:\Program Files (x86)
[2025-05-19 13:09:52,154] INFO - ty.detectors.UnityDetectorBase - Looking in: C:\Program Files (x86)\Unity\Hub\Editor

The found Unity versions are reported as the unity.path.%unityVersion% build agent configuration parameters. They can be checked in the TeamCity UI's Agents > %Agent Name% > Parameters page.

As the Unity versions are detected during the agent startup, the build agent must be restarted when new versions of Unity are installed.