Fix another dialyzer Kernel.with edge case

[sabiwara]

Close #13868

Note: I tried to add "generated" to a bunch of places, like to the call or to all else clauses, but it didn't fix it.
This ended up being the solution.

[fishtreesugar]

Should it be backported to the v1.17 branch?

[josevalim]

Backported, tks!

[sabiwara]

Good call @fishtreesugar, sorry I meant to do it and forgot 🙇

[NobbZ]

Backported, tks!

Any idea when a new version with the fix will be released? We are currently blocked updating because of this (and another issue, I am trying to create a reproducer for)

[codeadict]

Was this backported to 1.17.3?

[josevalim]

It was backported but no new release was made, as v1.18 was released slightly soon after.

[codeadict]

So in that case skipping 1.17 altogether and going to 1.18 would be the solution?

[sabiwara]

Just mentioning for the record, but there are several options that might be available depending on your situation:

• temporarily disabling this one (@dialyzer {:nowarn_function, {:x, 1}}) - sometimes not enough since callers might still be impacted
• temporarily trick dialyzer to ignore this one - see example below
• implement this refactoring suggestion (fixing the warning would just be a nice side effect)

Tricking dialyzer:
Adding an extra level of indirection is enough to lose dialyzer and consider anything as term()

  def x(arg) do
-    with {:foo, :ok} <- {:foo, foo(arg)},
+    with {:foo, :ok} <- Function.identity({:foo, foo(arg)}),
         {:bar, :ok} <- {:bar, bar(arg)} do

(you could implement your own def dialyzer_ignore(term), do: term)