We are delighted to announce the release of Cylc 8.6.0
This release contains one particularly notable change, Cylc IDs are no longer limited to matching n=0 tasks. For example, this means that cylc hold //1234/FAMILY will now hold all members of FAMILY not just the members that are presently held in the scheduler’s window.
The minimum Python version for all Cylc and Rose components has increased to 3.12.
For more information see: Changes — Cylc 8.6.0 documentation
We will announce all further releases in the Cylc 8.6 series in this thread.
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Hi all.
The 8.6 release is a big deal.
It marks the point where Cylc 8 definitively eclipses any advantage that Cylc 7 had.
(That’s specifically with regard to runtime interventions - Cylc 8 was better from the outset in almost every other respect).
For nostalgic Cylc 7 users: by sheer luck the inefficient (by Cylc 8 standards) Cylc 7 scheduler often made runtime interventions easier than might be expected, because it kept many more tasks in memory. Going beyond this “active window” of the workflow could be very difficult in Cylc 7, but often wasn’t necessary.
With task matching beyond the n=0active window in Cylc 8.6 we can now do all the powerful Cylc 8 interventions without worrying about whether the tasks involved are still in memory or not.
Relatedly, we are gradually adding specific advice to the User Guide Interventions section.
Cylc 7 is dead, long live Cylc 8! 
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Great news!
We are getting more and more to a point where user interventions are needed.
Any advice on upgrading Cylc site installation and workflows from 8.5 to 8.6 smoothly?
There are no changes that need to be made to workflow configurations - so just install Cylc 8.6 along side 8.5, and you’re good to go.
As advised here Installation — Cylc 8.6.0 documentation we recommend that you install a wrapper called cylc (just use the provided one and modify it a bit) that is in the default $PATH and selects which version to run based on environment (e.g., the latest version by default, or $CYLC_VERSION). Each separate version should be installed as a complete conda environment, with everything needed in it.
(Let us know if the instructions on that are not clear enough).
Thanks @hilary.j.oliver ! Yes, we are using the wrapper cylc script, so it sounds like it will be smooth. Do we need to stop and start workflows? Or do they carry over seamlessly?
With the wrapper script approach, you can add new Cylc deployments without affecting running workflows. Restart your workflows to pick up the latest version:
cylc stop --now --now <workflow-id>
cylc play <workflow-id>
We typically make the latest deployment the default one. Otherwise, use the CYLC_VERSION environment variable to change which version you are using. Cylc may prompt you to confirm the version upgrade, use the --upgrade option to bypass this.
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We have released cylc-flow 8.6.1, cylc-uiserver 1.8.1
These releases contain a number of bug fixes as well as some enhancements to the GUI, highlights:
- The tutorial workflows have changed data source (the old tutorials will become defunct shortly).
- The workflows sidebar in the Cylc GUI has been redesigned. The task state totals now reflect only the n=0 window As a result, they don’t change when the window is adjusted, and handled task failures are omitted from the totals.
- The memory usage of both cylc-flow and cylc-uiserver should have improved in certain situations.
- Fixed issues related to
cylc trigger and platform selection in paused workflows.
- Python 3.14 support.
A metomi-rose bugfix release will follow shortly.
How to update installations
How to update site installations
Sites should create a new environment for this release and manage parallel installations using the provided wrapper script .
How to update stand-alone installations
# First shut down running workflows:
cylc stop '*'
# For Conda managed environments:
conda install 'cylc-flow=8.6.1' 'cylc-uiserver=1.8.1'
# For Pip managed environments:
pip install 'cylc-flow==8.6.1' 'cylc-uiserver==1.8.1'
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We have released metomi-rose 2.6.2
This changes the Rose tutorials to use the same data source as the Cylc tutorials (migrating away from now defunct DataPoint).
How to update installations
How to update site installations
Sites should create a new environment for this release and manage parallel installations using the provided wrapper script .
How to update stand-alone installations
# First shut down running workflows:
cylc stop '*'
# For Conda managed environments:
conda install 'metomi-rose=2.6.2'
# For Pip managed environments:
pip install 'metomi-rose==2.6.2'
We have released cylc-flow 8.6.2, cylc-uiserver 1.8.2 and rose 2.6.3
The Cylc UI Server release provides several updates to the GUI, notably:
- The workflows sidebar now displays indicators if there are any held or retrying tasks in the active window.
- Task state filters now include task modifiers so we can now filter for “held” or “retrying” tasks.
- Task ID filters now accept globs.
- The command editor forms can be opened in a new tab (with the exception of broadcast).
how to update
How to update installations
How to update site installations
Sites should create a new environment for this release and manage parallel installations using the provided wrapper script .
How to update stand-alone installations
# First shut down running workflows:
cylc stop '*'
# For Conda managed environments:
conda install 'cylc-flow=8.6.1' 'cylc-uiserver=1.8.2' 'metomi-rose=2.6.6'
# For Pip managed environments:
pip install 'cylc-flow==8.6.1' 'cylc-uiserver==1.8.2' 'metomi-rose==2.6.6'