Might be caused by #19715 and that || Tail == 0

if (TotalCount == 0 || Tail == 0)
            {
                // Don't read anything
                return;

https://github.com/PowerShell/PowerShell/pull/19715/files#diff-0cf19feadd29d19fb01dcfe57f5fd9bd24be0d5fed7c1241f0cfa05da14c2fc1R90

GitHub

Get-Content -Head and -Tail disallow negative values and cleanup by CarloToso · Pull Request #19715 · PowerShell/PowerShell

PR Summary

Disallow negative values for -Head and -Tail
Add fast return if -Tail == 0
Cleanup code

TODO:

Add tests

PR Context
#19710 @jhoneill @mklement0

PR Checklist

PR has a meaningful ti...

Yes, it looks like the - meaningful and previously supported - combination of -Tail 0 with -Wait wasn't considered in the linked PR.
Correct, @CarloToso?

In my opinion, -Tail 0 -Wait is a super common use case.

Yes, it looks like the - meaningful and previously supported - combination of -Tail 0 with -Wait wasn't considered in the linked PR. Correct, @CarloToso?

It was an oversight on my part, I'll open a PR to fix it later. Should we also support -Head 0 with -Wait ?

Thanks, @CarloToso.

Yes, I'd say there's no reason to not also support -Head 0 (though probably an uncommon use case)

However, note that combining -Head with -Wait is currently fundamentally broken, which predates your PR (same behavior in WinPS).

The docs don't mention any mutual exclusion for -Wait (other than, sensibly, -Raw).

At least hypothetically, there could be - conceptually flawed - code out there that relies on -Wait being ignored in the presence of -Head / -TotalCount, though that strikes me as a bucket 3 change still worth making.
@SteveL-MSFT, any thoughts?

@CarloToso, a simple way forward is to fix the regression bug with respect to -Tail only.

The -Head case (if you will) can then be dealt with separately.

Update: See

• Get-Content: -Wait is ignored in combination with -Head #20781

Well, good thing I looked in the open bugs, was about to report the same issue :D

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