#5640 [BUG] flytekit fails when uppercase letters are used in workflow input names Issue created by ddl-rliu Proposed fix: flyteorg/flytekit#2656 Describe the bug When uppercase letters are used in workflow input names, e.g.

A

, it correctly generates a corresponding pyflyte workflow option flag

--A

, however the final workflow definition expects the input name

a

, which is lower case and thus leads to the following failing behavior:

$ pyflyte run --remote wf.py wf --A 1
Failed with Unknown Exception <class 'flytekit.core.type_engine.TypeTransformerFailedError'>
Reason: Python value cannot be None, expected <class 'int'>/<FlyteLiteral(LiteralType) simple: INTEGER>

Expected behavior One solution is to implement a fix which allows uppercase letters, however the

click

library, specifically

click.Option

, automatically lowercases option names. Therefore, a naive workaround may lead to other unintended/strange behaviors. Another solution, and the one proposed here – flyteorg/flytekit#2656 – is to add validation in flytekit to disallow uppercase letters in workflow input names. So uppercase letters will still cause an error, but the error message is much more sensible/actionable.

$ pyflyte run --remote wf.py wf --A 1
Failed with Unknown Exception <class 'ValueError'> Reason: Input name must be lowercase: 'A'

Additional context to reproduce

from flytekit import task, workflow

@task
def report_all_calculated_areas(
    area_shell: float,
):
    print(f"shell: area={area_shell}")

@workflow
def wf(A: float):
    report_all_calculated_areas(
        area_shell=A,
    )

pyflyte run --remote wf.py wf --A 1

Screenshots No response Are you sure this issue hasn't been raised already? • Yes Have you read the Code of Conduct? • Yes flyteorg/flyte