Octopus "Unable to find a machine/environment" in CI

Octopus could not resolve a machine or environment you named. The value passed to --deployTo or --specificMachines does not match any registered target or environment in the current space, often because of a typo, a wrong space, or a deleted target.

What this error means

octo fails with "Unable to find a machine named X" or "Unable to find the environment X" when deploying or targeting specific machines.

octo

octo deploy-release --project "Web" --deployTo "Staging" --specificMachines "web-01"
Unable to find a machine named 'web-01' in the environment 'Staging'.

Common causes

A mistyped or deleted target or environment name

The machine or environment name does not match a registered entity because it was renamed, deleted, or typed incorrectly.

The command targets the wrong space

The target exists in another space, but the command runs in the default space, so it is not found here.

How to fix it

Use names that exist in the target space

List targets and environments in the space to confirm exact names.
Match --deployTo and --specificMachines to those names.
Pass --space if the targets live in a non-default space.

Terminal

octo deploy-release --project "Web" --deployTo "Staging" \
  --space "Default" --server "$OCTOPUS_URL" --apiKey "$OCTOPUS_API_KEY"

Register the target if it is genuinely missing

If the machine was never registered or was removed, add it to the environment before targeting it in a deploy.

How to prevent it

Reference machines and environments by their exact registered names.
Set --space explicitly when using multiple spaces.
Keep pipelines updated when targets are renamed or removed.