Cylc Install

Does This Change Affect Me?

Almost certainly.

This change will affect you:

  • If you use rose suite-run to install and run Cylc workflows.

  • If you usually develop Cylc workflows in the ~/cylc-run directory.

  • If you develop Cylc workflows outside of the ~/cylc-run directory and manually copy the files to ~/cylc-run.


Cylc 7 ran workflows in ~/cylc-run/. You could develop your workflow in ~/cylc-run or copy it after developing it elsewhere. If you developed in the ~/cylc-run directory there was a risk that Cylc might alter your files. If you developed elsewhere you needed to install your workflows manually with another tool.

We designed Cylc 8 to help you keep your development and running copies separate. By default you can now develop workflows in the ~/cylc-src directory. As a result, you will not change your development copy by running a workflow. You will, however, need to install your workflow from ~/cylc-src to ~/cylc-run using the cylc install command.


If you have previously used Rose, cylc install functions in a similar way to rose suite-run --install-only.


  • You can install a workflow from inside the source directory:

    $ cd ~/cylc-src/my-workflow
    $ cylc install
    INSTALLED my-workflow/run1 from /home/me/cylc-src/my-workflow
  • You can install a workflow by providing the workflow source name (if the source directory is located in any of the Configurable Source Directories, e.g. ~/cylc-src):

    $ cylc install my-workflow
    INSTALLED my-workflow/run2 from /home/me/cylc-src/my-workflow
  • You can install a workflow by providing the path to the source directory:

    $ cylc install ~/cylc-src/my-workflow
    INSTALLED my-workflow/run3 from /home/me/cylc-src/my-workflow


Each time you run cylc install for a particular workflow, a new copy of the workflow is installed to a new run directory. In the example above, we created three run directories inside ~/cylc-run/my-workflow.

Once you have installed a workflow you can use cylc play to run it - see Running Workflows.

You can delete installed workflows using cylc clean - see Removing Workflows.

A .cylcignore file can be used to control which files cylc install transfers to the installed workflow, see 1. File Installation for details.

Remote Installation

Remote file installation does not occur until running the workflow. When the first task runs on a remote platform, Cylc will transfer files from the run directory to the install target.

If you have used Rose 2019, you may be used to all files and directories in the run directory being included. However, Cylc 8 will only copy the ana, app, bin, etc and lib directories by default (in addition to authentication files in .service). If you want to include custom files and directories in remote installation, use flow.cylc[scheduler]install.


If you need to ensure your workflow is still interoperable with Cylc 7, wrap it in a Jinja2 check like so:

{% if CYLC_VERSION is defined and CYLC_VERSION[0] == '8' %}
    install = my-dir/, my-file
{% endif %}

See the user guide for more details.


If you have tasks that mirror/copy the run directory to a remote platform (such as FCM make tasks), this can cause conflicts with symlink directory setup.

You can find out if symlink directories are configured for the platform by running:

cylc config -i '[install][symlink dirs][<platform-name>]'

The recommended workaround is to use a “dummy” task that runs on the particular platform before any such mirror tasks in order to setup symlink directories, but without running anything.

For example:

        R1 = hpc_init => fcm_make

        platform = <platform-name>
        script = true

Migrating From rose suite-run

The rose suite-run command has been replaced by cylc install.

# rose 2019 / Cylc 7
$ rose suite-run

# rose 2 / Cylc 8
$ cylc install
$ cylc play <id>

Support for the rose-suite.conf file is provided by the Cylc Rose plugin which must be installed for Rose integration.


See the Installation section for instructions.

If Cylc Rose is installed it should appear in the list of installed Cylc plugins:

$ cylc version --long
8.0 (/path/to/cylc-8)

    cylc-rose       0.1.1   /path/to/cylc-rose

Notable differences to rose suite-run

Command line options:

The cylc install command remembers any options specified on the command line including Rose optional configurations and template variables and automatically applies them with future re-installations.

Rose Stem:

The rose stem command is provided by Cylc Rose. Like rose suite-run, rose stem used to install and run workflows. It now only installs the workflow which can then be run with cylc play.

See the Rose Stem documentation for more information.

Roses directory:

By default cylc install looks for workflows in ~/cylc-src, you you may want to add ~/roses to the list of global.cylc[install]source dirs.

Remote Installation:

With Rose 2019 / rose suite-run, files were installed on remote platforms before the workflow started running.

With Rose 2 / cylc install, files are installed on remote platforms just before the first task runs on that platform.

Rose used to install the entire workflow run directory to remote platforms. It now only installs configured directories for efficiency. See Remote Installation above for details.