# Cylc 8 Migration **URL:** https://cylc.discourse.group/c/cylc/7-to-8/13.md [Latest](https://cylc.discourse.group/latest.md) · [Categories](https://cylc.discourse.group/categories.md) --- ## [About the Cylc 8 Migration category](https://cylc.discourse.group/t/about-the-cylc-8-migration-category/326)
**Author:** [@oliver.sanders](https://cylc.discourse.group/u/oliver.sanders)\ **Replies:** 0
This category is for the migration from Cylc 7 (and Rose 2019) to Cylc 8. Workflows. System setup. Installation. Etc. --- ## [Run workflow template again from later cycle\_point](https://cylc.discourse.group/t/run-workflow-template-again-from-later-cycle-point/1222)
**Author:** [@schaferk](https://cylc.discourse.group/u/schaferk)\ **Replies:** 6\ **Last updated:** [August 4, 2025, 10:03pm UTC](https://cylc.discourse.group/t/run-workflow-template-again-from-later-cycle-point/1222 "2025-08-04T22:03:38Z")
Question: How to run same template workflow at a later cycle point via cylc play ... We have a template Cylc workflow that is (initially) run at an initial point using: cylc play \\ -s BOB="bob" \\ -s ALICE="alice" \\ … --- ## [Migrating from cylc7 to cylc8 (rose-suite.conf, graph, template variables)](https://cylc.discourse.group/t/migrating-from-cylc7-to-cylc8-rose-suite-conf-graph-template-variables/1188)
**Author:** [@Siegfried](https://cylc.discourse.group/u/Siegfried)\ **Replies:** 4\ **Last updated:** [June 13, 2025, 8:28am UTC](https://cylc.discourse.group/t/migrating-from-cylc7-to-cylc8-rose-suite-conf-graph-template-variables/1188 "2025-06-13T08:28:41Z")
cylc validate . gives hundreds of warning messages, but lets start with the first one: WARNING - 'rose-suite.conf\[jinja2:suite.rc\]' is deprecated. Use \[template variables\] instead. I have no idea what I need to do wi… --- ## [Beginning to use 8.4](https://cylc.discourse.group/t/beginning-to-use-8-4/1139)
**Author:** [@schaferk](https://cylc.discourse.group/u/schaferk)\ **Replies:** 9\ **Last updated:** [March 19, 2025, 4:01pm UTC](https://cylc.discourse.group/t/beginning-to-use-8-4/1139 "2025-03-19T16:01:47Z")
finally migrated to 8. having at least 2 issues: (cylc8) bash-4.4$ cylc show simple ClientTimeout: Timeout waiting for server response. This could be due to network or server issues. You might want to increase the … --- ## [Migration: unbound variable](https://cylc.discourse.group/t/migration-unbound-variable/1133)
**Author:** [@bblay](https://cylc.discourse.group/u/bblay)\ **Replies:** 2\ **Last updated:** [March 7, 2025, 1:16pm UTC](https://cylc.discourse.group/t/migration-unbound-variable/1133 "2025-03-07T13:16:54Z")
Hi, migrating to cylc 8, I have a missing environment variable. Cylc is invoked something like this: export OPT\_NAME=test\_quick cylc vip --verbose The variable is used in rose-suite.conf: PLOT\_DIR="$DATADIR/res\_cylc\_… --- ## [No more warnings for namespaces in runtime which aren't used in the graph?](https://cylc.discourse.group/t/no-more-warnings-for-namespaces-in-runtime-which-arent-used-in-the-graph/1124)
**Author:** [@TomC](https://cylc.discourse.group/u/TomC)\ **Replies:** 1\ **Last updated:** [February 20, 2025, 9:20am UTC](https://cylc.discourse.group/t/no-more-warnings-for-namespaces-in-runtime-which-arent-used-in-the-graph/1124 "2025-02-20T09:20:02Z")
In Cylc7, with -v option on, cylc validate would print a WARNING - task "qwerty" not used in the graph. In Cylc8, I don’t think this warning exists anymore. Is there an option to print out runtime entries which do not ex… --- ## [Optional task - not optional outputs?](https://cylc.discourse.group/t/optional-task-not-optional-outputs/1101)
**Author:** [@TomC](https://cylc.discourse.group/u/TomC)\ **Replies:** 2\ **Last updated:** [January 16, 2025, 12:30am UTC](https://cylc.discourse.group/t/optional-task-not-optional-outputs/1101 "2025-01-16T00:30:16Z")
Is there a way to have a task be optional to even run? I’ve tried having a ? after a task which doesn’t get triggered, but, that doesn’t work - I believe optional outputs require a task to at least run. For example, say… --- ## [Relationship between \[host self-identification\] and \[platforms\]](https://cylc.discourse.group/t/relationship-between-host-self-identification-and-platforms/1098)
**Author:** [@areinecke](https://cylc.discourse.group/u/areinecke)\ **Replies:** 3\ **Last updated:** [January 13, 2025, 9:04pm UTC](https://cylc.discourse.group/t/relationship-between-host-self-identification-and-platforms/1098 "2025-01-13T21:04:51Z")
On our cray-based systems the compute nodes see the login nodes with a different IP address than what the login node self identifies with. This was dealt with in Cylc v7 by using the hardwired option in \[suite host self… --- ## [Rerun an R1 task many cycles later](https://cylc.discourse.group/t/rerun-an-r1-task-many-cycles-later/1084)
**Author:** [@TomC](https://cylc.discourse.group/u/TomC)\ **Replies:** 5\ **Last updated:** [January 2, 2025, 10:20pm UTC](https://cylc.discourse.group/t/rerun-an-r1-task-many-cycles-later/1084 "2025-01-02T22:20:25Z")
Say you have an R1 task which sets up some information. At some point in the future, hundreds of cycles later, you need to rerun it to re-set the information up based on some change. How does one do this? In Cylc 7, I c… --- ## [Cylc workflow path variables do not resolve symlinks](https://cylc.discourse.group/t/cylc-workflow-path-variables-do-not-resolve-symlinks/1028)
**Author:** [@annette.osprey](https://cylc.discourse.group/u/annette.osprey)\ **Replies:** 8\ **Last updated:** [October 4, 2024, 6:48am UTC](https://cylc.discourse.group/t/cylc-workflow-path-variables-do-not-resolve-symlinks/1028 "2024-10-04T06:48:09Z")
I’ve noticed that in Cylc 8 variables such as $CYLC\_WORKFLOW\_RUN\_DIR do not resolve symlinks that have been configured for the platform. To double check with a simple example, I set up a config file like this: \[install… --- ## [How to pre-prepare data in share before starting a workflow?](https://cylc.discourse.group/t/how-to-pre-prepare-data-in-share-before-starting-a-workflow/961)
**Author:** [@TomC](https://cylc.discourse.group/u/TomC)\ **Replies:** 3\ **Last updated:** [June 4, 2024, 11:26pm UTC](https://cylc.discourse.group/t/how-to-pre-prepare-data-in-share-before-starting-a-workflow/961 "2024-06-04T23:26:58Z")
If I want to warm-start a workflow by pre-preparing the share area on disk, I am getting a failure. 2024-06-03T07:43:26Z DEBUG - \['ssh', '-oBatchMode=yes', '-oConnectTimeout=10', 'remote.host', 'env', 'CYLC\_VERSION=8.2.… --- ## [CYLC\_SUITE\_DEF\_PATH analogue in Cylc 8](https://cylc.discourse.group/t/cylc-suite-def-path-analogue-in-cylc-8/932)
**Author:** [@funkapus](https://cylc.discourse.group/u/funkapus)\ **Replies:** 5\ **Last updated:** [April 10, 2024, 2:51pm UTC](https://cylc.discourse.group/t/cylc-suite-def-path-analogue-in-cylc-8/932 "2024-04-10T14:51:04Z")
Hi. I understand that CYLC\_SUITE\_DEF\_PATH from Cylc 7 is obsolete in Cylc 8. However, I don’t see any kind of analog in Cylc 8 that points to the location of the installed workflow (which under normal conditions might … --- ## [Why does the runahead limit in c8 show a difference number to c7?](https://cylc.discourse.group/t/why-does-the-runahead-limit-in-c8-show-a-difference-number-to-c7/921)
**Author:** [@jonnyhtw](https://cylc.discourse.group/u/jonnyhtw)\ **Replies:** 2\ **Last updated:** [March 24, 2024, 10:00pm UTC](https://cylc.discourse.group/t/why-does-the-runahead-limit-in-c8-show-a-difference-number-to-c7/921 "2024-03-24T22:00:03Z")
hi i’m porting a workflow to c8 and i’m getting this warning when i run cylc val . WARNING - \* (8.0.0) \[scheduling\]max active cycle points -\> \[scheduling\]runahead limit - "4" -\> "P3" why is the number different? tha… --- ## [Cylc7 vs 8 - adding new tasks to a graph changes](https://cylc.discourse.group/t/cylc7-vs-8-adding-new-tasks-to-a-graph-changes/850)
**Author:** [@TomC](https://cylc.discourse.group/u/TomC)\ **Replies:** 6\ **Last updated:** [January 9, 2024, 11:01am UTC](https://cylc.discourse.group/t/cylc7-vs-8-adding-new-tasks-to-a-graph-changes/850 "2024-01-09T11:01:26Z")
Hi, I was wondering how Cylc8 differs to Cylc7 when adding new tasks to an active workflow? In Cylc7, if you modify the graph to add new tasks, you had either Insert the new tasks manually from CLI, and force trigger … --- ## [Compatability mode and remote symlink dirs](https://cylc.discourse.group/t/compatability-mode-and-remote-symlink-dirs/837)
**Author:** [@annette.osprey](https://cylc.discourse.group/u/annette.osprey)\ **Replies:** 3\ **Last updated:** [December 20, 2023, 9:36am UTC](https://cylc.discourse.group/t/compatability-mode-and-remote-symlink-dirs/837 "2023-12-20T09:36:45Z")
Hi, On our HPC (ARCHER2) the batch nodes can’t see the /home file system. Therefore we symlink the cylc-run directories to $DATADIR (the user’s space on /work that the batch nodes can see). In Cylc 7 we did this throug… --- ## [Stop cylc deleting files on remote?](https://cylc.discourse.group/t/stop-cylc-deleting-files-on-remote/834)
**Author:** [@TomC](https://cylc.discourse.group/u/TomC)\ **Replies:** 3\ **Last updated:** [December 14, 2023, 9:42am UTC](https://cylc.discourse.group/t/stop-cylc-deleting-files-on-remote/834 "2023-12-14T09:42:12Z")
In Cylc7/rose, when using rose suite-run, files are copied over to the remote. Old files which no longer (or never have) existed in the local area do not get touched. In Cylc8, you are using the --delete option to remove… --- ## [\`suite\_state\` trigger in Cylc8 compatibility mode](https://cylc.discourse.group/t/suite-state-trigger-in-cylc8-compatibility-mode/816)
**Author:** [@ukmo-ccbunney](https://cylc.discourse.group/u/ukmo-ccbunney)\ **Replies:** 4\ **Last updated:** [November 23, 2023, 9:50am UTC](https://cylc.discourse.group/t/suite-state-trigger-in-cylc8-compatibility-mode/816 "2023-11-23T09:50:57Z")
Hello! I have a cylc7 suite that I am trying to run using Cylc8 in backward compatibility mode. However, it fails to validate my inter-suite XTrigger: \[\[xtriggers\]\] upstream\_amm15 = suite\_state( ... ):PT10M w… --- ## [Debug a stalling suite that uses expiring tasks](https://cylc.discourse.group/t/debug-a-stalling-suite-that-uses-expiring-tasks/811)
**Author:** [@fredw](https://cylc.discourse.group/u/fredw)\ **Replies:** 6\ **Last updated:** [November 23, 2023, 5:35am UTC](https://cylc.discourse.group/t/debug-a-stalling-suite-that-uses-expiring-tasks/811 "2023-11-23T05:35:11Z")
I am porting my old cylc7 suites to cylc8. Here I am describing an issues I was facing when my workflow stalled and never progresses past the initial cycle point. I’m starting the suite with extract from rose-suite.co… --- ## [Migrating clock-triggers from cylc7 to cylc8](https://cylc.discourse.group/t/migrating-clock-triggers-from-cylc7-to-cylc8/807)
**Author:** [@fredw](https://cylc.discourse.group/u/fredw)\ **Replies:** 5\ **Last updated:** [November 17, 2023, 11:14am UTC](https://cylc.discourse.group/t/migrating-clock-triggers-from-cylc7-to-cylc8/807 "2023-11-17T11:14:48Z")
Hello, Can you help me convert clock-triggers from old-style cylc7 syntax to the new-style cylc8 style? I see lots of very strange behaviour in my suites when running in cylc8 and I suspect it’s not dealing with clock-t… --- ## [Dependencies during boostrapping (R1 tasks)](https://cylc.discourse.group/t/dependencies-during-boostrapping-r1-tasks/798)
**Author:** [@fredw](https://cylc.discourse.group/u/fredw)\ **Replies:** 19\ **Last updated:** [November 16, 2023, 7:57pm UTC](https://cylc.discourse.group/t/dependencies-during-boostrapping-r1-tasks/798 "2023-11-16T19:57:58Z")
I am seeing odd behaviour in a suite I’m porting from cylc7 to cyl8 concerning the boostrapping section. The logic I’m trying to achieve is explained in an earlier question \[Controlling which R1 tasks run upon bootstrap… --- ## [Jinja variables in rose stem cylc8 compatibility mode](https://cylc.discourse.group/t/jinja-variables-in-rose-stem-cylc8-compatibility-mode/780)
**Author:** [@srennie](https://cylc.discourse.group/u/srennie)\ **Replies:** 6\ **Last updated:** [October 13, 2023, 8:37am UTC](https://cylc.discourse.group/t/jinja-variables-in-rose-stem-cylc8-compatibility-mode/780 "2023-10-13T08:37:09Z")
I’m trying to run UM (13.0) rose-stem and the suite is failing to validate or play due to undefined Jinja2 variables. I haven’t used compatibility mode before, and I also haven’t run UM rose-stem before, so I don’t know… --- ## [Replacement for \`cylc status\`](https://cylc.discourse.group/t/replacement-for-cylc-status/779)
**Author:** [@ejhyer](https://cylc.discourse.group/u/ejhyer)\ **Replies:** 2\ **Last updated:** [October 12, 2023, 5:33pm UTC](https://cylc.discourse.group/t/replacement-for-cylc-status/779 "2023-10-12T17:33:32Z")
Hello cylc wizards, I looked through the options described in cylc help all and did not see a utility that provides what cylc status did, namely, a scriptable means to determine if a flow is running, stalled, or stopped… --- ## [Cylc8 migration issues](https://cylc.discourse.group/t/cylc8-migration-issues/733)
**Author:** [@fredw](https://cylc.discourse.group/u/fredw)\ **Replies:** 36\ **Last updated:** [October 5, 2023, 9:13pm UTC](https://cylc.discourse.group/t/cylc8-migration-issues/733 "2023-10-05T21:13:06Z")
Hello, I’m finally gettin round to migrating to cylc8, but so far I haven’t been able to get even the simplest tasks working. The documentation is rather sparse on trobleshooting and also makes it hard to figure out sim… --- ## [Preview job script in cylc8?](https://cylc.discourse.group/t/preview-job-script-in-cylc8/734)
**Author:** [@TomC](https://cylc.discourse.group/u/TomC)\ **Replies:** 5\ **Last updated:** [August 25, 2023, 8:59am UTC](https://cylc.discourse.group/t/preview-job-script-in-cylc8/734 "2023-08-25T08:59:40Z")
Hi, If I want to preview a job script without submitting, how do I do this in Cylc8? In Cylc7 I would do cylc submit --dry-run. Thanks. --- ## [Cannot have more than 1 repetition for zero-duration recurrence](https://cylc.discourse.group/t/cannot-have-more-than-1-repetition-for-zero-duration-recurrence/705)
**Author:** [@jonnyhtw](https://cylc.discourse.group/u/jonnyhtw)\ **Replies:** 15\ **Last updated:** [August 1, 2023, 4:55am UTC](https://cylc.discourse.group/t/cannot-have-more-than-1-repetition-for-zero-duration-recurrence/705 "2023-08-01T04:55:31Z")
hey there, i’m porting a job to cylc 8 and am getting this at cylc val time… \> cylc val . WARNING - Cannot have more than 1 repetition for zero-duration recurrence 19500101T0000Z. Valid for cylc-8.1.4 19500101T0000Z i… --- ## [Rerun 2 tasks which depend on one another in one command?](https://cylc.discourse.group/t/rerun-2-tasks-which-depend-on-one-another-in-one-command/697)
**Author:** [@jonnyhtw](https://cylc.discourse.group/u/jonnyhtw)\ **Replies:** 4\ **Last updated:** [July 17, 2023, 5:31am UTC](https://cylc.discourse.group/t/rerun-2-tasks-which-depend-on-one-another-in-one-command/697 "2023-07-17T05:31:00Z")
hi there, i need to run an fcm\_make and an fcm\_make2 task multiple times in a development workflow and fcm\_make2 can only run if fcm\_make has completed successfully. in cylc 7 i would’ve set both of their states to ‘wa… --- ## [Couldn't see event handler logs in console with Cylc v8.1.4](https://cylc.discourse.group/t/couldnt-see-event-handler-logs-in-console-with-cylc-v8-1-4/688)
**Author:** [@amaresh494](https://cylc.discourse.group/u/amaresh494)\ **Replies:** 1\ **Last updated:** [July 7, 2023, 2:32pm UTC](https://cylc.discourse.group/t/couldnt-see-event-handler-logs-in-console-with-cylc-v8-1-4/688 "2023-07-07T14:32:20Z")
Description I’m trying to capture a few events when a Cylc workflow is running and dump them in Kafka after processing the data collected. In previous versions of Cylc from v7+ to v8.0.\*, I could see the logs in the cons… --- ## [\--yes option for cylc vr?](https://cylc.discourse.group/t/yes-option-for-cylc-vr/656)
**Author:** [@jonnyhtw](https://cylc.discourse.group/u/jonnyhtw)\ **Replies:** 2\ **Last updated:** [May 22, 2023, 9:27pm UTC](https://cylc.discourse.group/t/yes-option-for-cylc-vr/656 "2023-05-22T21:27:39Z")
hey there, is there any reason why there isn’t a --yes option for cylc vr like there is for cylc clean? just wondering if this was an active decision in the development process? cheers, jonny --- ## [Suite stuck after fixing graph issue](https://cylc.discourse.group/t/suite-stuck-after-fixing-graph-issue/651)
**Author:** [@srennie](https://cylc.discourse.group/u/srennie)\ **Replies:** 8\ **Last updated:** [May 16, 2023, 8:40am UTC](https://cylc.discourse.group/t/suite-stuck-after-fixing-graph-issue/651 "2023-05-16T08:40:55Z")
I have a workflow (full DA cycling workflow) that got stuck because I had missed a connection in my graph. After fixing it, I restarted, but got an error. 2023-05-15T01:21:43Z ERROR - ('20230314T0600Z', 'sy\_um\_fcst\_ss\_0… --- ## [Why do i need to 'reload' after running 'cylc vr'?](https://cylc.discourse.group/t/why-do-i-need-to-reload-after-running-cylc-vr/648)
**Author:** [@jonnyhtw](https://cylc.discourse.group/u/jonnyhtw)\ **Replies:** 3\ **Last updated:** [May 11, 2023, 7:25am UTC](https://cylc.discourse.group/t/why-do-i-need-to-reload-after-running-cylc-vr/648 "2023-05-11T07:25:50Z")
hi there, i often need to reload a running workflow definition (e.g. changing run length) and so i am using cylc vr to do so. i don’t understand why i need to then run cylc reload command afterwards since the docs say… … [Next page](https://cylc.discourse.group/c/cylc/7-to-8/13.md?page=1)