I am sorry to hear that debhelper is causing you issues.
> I just wanted to point out that Ubuntu uses autopkgtests to check
> uploads before allowing them into the regular development repository.
> This bug is causing a very large number of autopkgtests to fail, which
> is disrupting Ubuntu development work. Generally, anything outputted
> to stderr will fail the autopkgtest.
> Could you not emit that warning to stderr especially since I see only
> one package using compat 11 now?
Sorry, but that argument is not enough to convince me that removing the
warning in Debian is a good solution.
* dh-acc is relying on a broken implementation detail that is being
phased out. I would expect a warning in such situations.
* At compat 11 this behaviour becomes an error, so it would ruin the
point of the warning if we "wait" until compat 11.
* The change to dh-acc is literally a 3-line change and would solve
this issue as well (the process described in my original mail). This
change is compatible with all supported versions of debhelper.
Again, I understand your frustration, but I think the proper fix is at
the level where it would be faster to deploy than further discussion,
very trivial to do and with plenty of test cases.