Raising UnsupportedFeatureError instead of InvalidResourceSpecification on passing resource_specification to HTEX

[Harichandra-Prasath]

Description

Currently in Parsl, HTEX doesnt support resource_specification and upon passing , it will raise InvalidResourceSpecification from mpi_prefix_compose. Similar behaviour can be seen in ThreadPoolExecutor but instead of raising InvalidResourceSpecification , it raises UnsupportedFeatureError from parsl.executors.error. So, Ideally HTEX should do the same,

Changed Behaviour

From this PR, HTEX will raise the same when resource_specification is passed to it. Moreover UnsupportedFeatureError is changed slightly to support suggestions for the users when for the feature.

Fixes

Fixes #3589

Type of change

• Code maintenance/cleanup

[benclifford]

@Harichandra-Prasath my intention was that all of these errors are reported as InvalidResourceSpecification, not that they all become unsupported feature errors. The user gets more information by being told that this is an invalid resource specification.

[Harichandra-Prasath]

So, you suggest parsl should raise InvalidResourceSpecification whenever resource_spec is passed to ThreadPoolExecutor? Any specific reasons? I believe resource_spec is not supported in HTEX and ThreadPoolExecutor. Instead of UnSupportedFeature , if InvalidResourceSpecification is raised, doesnt it implies whatever shared is invalid rather than underlying executors doesnt support it.

[benclifford]

There are upcoming uses for resource specification in the High Throughput Executor -- see PR #3575 which uses it for task priority.