When missing add name of argument for command to error message

[zpittmansf]

Instead of "Required argument missing for command: {commandname}", provide "Required argument {argumentname} missing for command: {commandname}" for better clarity as to which required argument is missing.

command-line-api/src/System.CommandLine/ValidationMessages.cs

Line 53 in a521704

? $"Required argument missing for command: {symbolResult.Token().Value}"

[Forge36]

@Drizin appears to have a proof of concept 49371bc. What additional changes or review is needed?

From reviewing: CONTRIBUTING.md

• A minimal reproduction - Is this required in this instance?
• Unit Tests
• Breaking Changes? (This doesn't appear to be, I haven't dug in to confirm with testing)

[Drizin]

@Forge36 thanks for bringing this.
I've just submitted PR 1993 with that improvement.

[TMUNYU]

Any news on this issue? Seems the PR has been open a while now

[samblackburn]

I've opened a new PR since the last one died - is anyone happy to review it?