Are you using the CYLC_TASK_DEPENDENCIES environment variable? Please tell us.

CYLC_TASK_DEPENDENCIES is exported into the job environment, it holds the IDs of the prerequisites that triggered the task. We have had to redact this variable for tasks where there are more than 50 prerequisites as this can cause the environment variable to become long enough to cause some commands to fail (e.g. env & ls).

The people who requested this feature have since stopped using it, we’re not sure whether anyone is utilising this. Due to the fundamental flaw of trying to communicate a potentially large amount of information in an environment variable, we are considering retiring it.

There is an alternative way to access this information using cylc show --json. This returns a list of the task’s prerequisites and their statuses.

Please let us know if you are using this variable and what the use case is so that we can ensure we maintain any required functionalities.

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