Exceptions

Exceptions for “expected” errors.

exception cylc.flow.exceptions.ClientError(message, traceback=None, workflow=None)

Base class for errors raised by Cylc client instances.

For example, the workflow you are trying to connect to is stopped.

Parameters:

• message (str)

• traceback (str | None)

• workflow (str | None)

message

The exception message.

traceback

The underlying exception instance if available.

workflow

The workflow ID if available.

exception cylc.flow.exceptions.ClientTimeout(message, workflow=None)

The scheduler did not respond within the timeout.

This could be due to: * Network issues. * Scheduler issues. * Insufficient timeout.

To increase the timeout, use the --comms-timeout option.

Parameters:

• message (str)

• workflow (str | None)

exception cylc.flow.exceptions.CommandFailedError(value)

Exception for when scheduler commands fail.

Parameters:

value (str | Exception)

exception cylc.flow.exceptions.CyclerTypeError(*args)

An error raised when incompatible cycling types are wrongly mixed.

exception cylc.flow.exceptions.CyclingError

Base class for errors in cycling configuration.

exception cylc.flow.exceptions.CylcConfigError

Generic exception to handle an error in a Cylc configuration file.

exception cylc.flow.exceptions.CylcError

Generic exception for Cylc errors.

This exception is raised in-place of “expected” errors where a short message to the user is more appropriate than traceback.

CLI commands will catch this exception and exit with str(exception).

exception cylc.flow.exceptions.CylcMissingContextPointError

An error denoting a missing (but required) context cycle point.

exception cylc.flow.exceptions.CylcMissingFinalCyclePointError

An error denoting a missing (but required) final cycle point.

exception cylc.flow.exceptions.CylcTimeSyntaxError

An error denoting invalid ISO/Cylc input syntax.

exception cylc.flow.exceptions.CylcVersionError(version=None)

Contact file is for a Cylc Version not supported by this script.

exception cylc.flow.exceptions.FileRemovalError(exc)

Exception for errors during deletion of files/directories, which are probably the filesystem’s fault, not Cylc’s.

Parameters:

exc (Exception)

Return type:

None

exception cylc.flow.exceptions.GlobalConfigError

Exception for configuration errors in a Cylc global configuration.

exception cylc.flow.exceptions.GraphParseError

Exception for errors in Cylc workflow graphing.

exception cylc.flow.exceptions.HostSelectException(data, ranking=None)

No hosts could be selected from the provided configuration.

Parameters:

• data (Dict[str, dict]) – Mapping of hostnames to error info.

• ranking (str | None) – The ranking expression used to select the host.

get_hint()

Return a hint to explain this error for certain cases.

Return type:

str | None

exception cylc.flow.exceptions.InputError

Exception covering erroneous user input to a Cylc interface.

Ideally this would be handled in the interface (e.g. argument parser). If this isn’t possible raise InputError.

exception cylc.flow.exceptions.IntervalParsingError(*args)

An error raised when an interval has an incorrect value.

exception cylc.flow.exceptions.InvalidCompletionExpression(message, expr=None)

For the [runtime][<namespace>]completion configuration.

Raised when non-whitelisted syntax is present.

exception cylc.flow.exceptions.NoHostsError(platform)

None of the hosts of a given platform were reachable.

exception cylc.flow.exceptions.NoPlatformsError(identity, hosts_consumed, set_type='group', place='')

None of the platforms of a given set were reachable.

Parameters:

• identity (str) – The name of the platform group or install target.

• set_type (str) – Whether the set of platforms is a platform group or an install target.

• place (str) – Where the attempt to get the platform failed.

• hosts_consumed (Set[str])

exception cylc.flow.exceptions.ParamExpandError

Exception for errors in Cylc parameter expansion.

exception cylc.flow.exceptions.PlatformError(message, platform_name, *, ctx=None, cmd=None, ret_code=None, out=None, err=None)

Error in the management of a remote platform.

If the exception represents a command failure, provide either the ctx OR manually populate the remaining kwargs. Otherwise leave the kwargs blank.

Parameters:

• message (str) – Short description.

• platform_name (str) – Name of the platform.

• ctx (Optional[SubFuncContext]) – SubFuncContext object if available. The other kwargs are derived from this.

• cmd (str | Sequence[str] | None) – The remote command.

• ret_code (int | None) – The command’s return code.

• out (str | None) – The command’s stdout.

• err (str | None) – The command’s stderr.

Return type:

None

exception cylc.flow.exceptions.PlatformLookupError

Unable to determine the correct job platform from the information given

exception cylc.flow.exceptions.PluginError(entry_point, plugin_name, exc)

Represents an error arising from a Cylc plugin.

Parameters:

• entry_point (str) – The plugin entry point as defined in setup.cfg (e.g. ‘cylc.main_loop’)

• plugin_name (str) – Name of the plugin

• exc (Exception) – Original exception caught when trying to run the plugin

exception cylc.flow.exceptions.PointParsingError(*args)

An error raised when a point has an incorrect value.

exception cylc.flow.exceptions.RequestError(message, workflow_cylc_version=None)

Represents an error handling a request, returned by the server.

Parameters:

• message (str)

• workflow_cylc_version (str | None)

exception cylc.flow.exceptions.SchedulerAlive

Workflow contact file exists and scheduler is alive.

exception cylc.flow.exceptions.SequenceDegenerateError(*args)

An error raised when adjacent points on a sequence are equal.

exception cylc.flow.exceptions.SequenceParsingError

Error on parsing an invalid sequence.

exception cylc.flow.exceptions.ServiceFileError

Exception for errors related to workflow service files.

exception cylc.flow.exceptions.TaskDefError

Exception raise for errors in TaskDef initialization.

exception cylc.flow.exceptions.TaskProxySequenceBoundsError(msg)

Error on TaskProxy.__init__ with out of sequence bounds start point.

exception cylc.flow.exceptions.TriggerExpressionError

Trigger expression syntax issue.

exception cylc.flow.exceptions.WorkflowConfigError

Exception for configuration errors in a Cylc workflow configuration.

exception cylc.flow.exceptions.WorkflowEventError

Exception for errors in Cylc event handlers.

exception cylc.flow.exceptions.WorkflowFilesError

Exception for errors related to workflow files/directories.

exception cylc.flow.exceptions.WorkflowStopped(workflow)

The Cylc scheduler you attempted to connect to is stopped.

exception cylc.flow.exceptions.XtriggerConfigError(label, func, message)

An error in an xtrigger.

For example:

• If the function module was not found.

• If the function was not found in the xtrigger module.

• If the function is not callable.

• If any string template in the function context arguments are not present in the expected template values.

Parameters:

• label (str)

• func (str)

• message (str | Exception)

exception cylc.flow.parsec.exceptions.FileParseError(reason, index=None, line=None, lines=None, err_type=None, fpath=None, help_lines=None)

Error raised when attempting to read in the config file(s).

Parameters:

• reason (str) – Description of error.

• err_type (str | None) – Classification of error (e.g. Jinja2Error).

• help_lines (Iterable[str] | None) – Additional info to include in the exception.

• lines (Dict[str, List[str]] | None) – (preferred) Dictionary in the format {filename: [context_line, …, error_line]}

• index (int | None) – The line number of the error in the config (counting from the shebang line not the first line).

• line (str | None) – The line of the error in the config.

• fpath (str | None) – The path to the file containing the error.

exception cylc.flow.parsec.exceptions.IllegalItemError(keys, key, msg=None, exc=None)

Bad setting section or option name.

exception cylc.flow.parsec.exceptions.IllegalValueError(vtype, keys, value, exc=None, msg=None)

Bad setting value.

exception cylc.flow.parsec.exceptions.IncludeFileNotFoundError(flist)

Error raised for missing include files.

exception cylc.flow.parsec.exceptions.InvalidConfigError(item, specname)

Error raised for missing configuration items.

exception cylc.flow.parsec.exceptions.ItemNotFoundError(item)

Error raised for missing configuration items.

exception cylc.flow.parsec.exceptions.Jinja2Error(exception, lines=None, filename=None)

Wrapper class for Jinja2 exceptions.

Parameters:

• exception (Exception) – The exception being re-raised

• lines (Dict[str, List[str]] | None) – Dictionary in the format {filename: [context_line, …, error_line]}

• filename (str | None) – Alternative to “lines” where less detail is available.

exception cylc.flow.parsec.exceptions.ListValueError(keys, value, msg=None, exc=None)

Bad setting value, for a comma separated list.

exception cylc.flow.parsec.exceptions.NotSingleItemError(item)

Error raised if an iterable is given where an item is expected.

exception cylc.flow.parsec.exceptions.ParsecError

Generic exception for Parsec errors.

schd_expected: bool = False

Set this flag to True on the exception if it is anticipated during Cylc Scheduler run (apart from loading of config we do not expect ParsecErrors during runtime).

exception cylc.flow.parsec.exceptions.TemplateVarLanguageClash(reason, index=None, line=None, lines=None, err_type=None, fpath=None, help_lines=None)

Multiple workflow configuration templating engines configured.

Parameters:

• reason (str)

• index (int | None)

• line (str | None)

• lines (Dict[str, List[str]] | None)

• err_type (str | None)

• fpath (str | None)

• help_lines (Iterable[str] | None)

exception cylc.flow.parsec.exceptions.UpgradeError

Error raised upon fault in an upgrade operation.

exception cylc.flow.parsec.exceptions.ValidationError(keys, value=None, msg=None, exc=None, vtype=None, key=None)

Generic exception for invalid configurations.