`eval` cannot nest calls

[shamilatesoglu]

IsExternallySynced(*GetDevice())
  -- Nested function evaluation not supported.

Two calls where one would do: the intermediate has to be materialized and pasted into the
next expression. Not a blocker, but it appears whenever an object is reached through an
accessor, which in C++ is most of the time.

If this is a limitation of the underlying expression evaluator rather than a server
choice, saying so in the message would help. The current wording reads like the server
declined to try.

[shamilatesoglu]

Leaving this open, because I could not reproduce it and would rather say so than close it on a guess.

An advice message for the refusal shipped in 0.3.0: when the evaluator says it will not run a nested call, the reply now says whose limit that is and suggests evaluating the inner call first and writing its result into the outer one. It costs nothing when it does not match, because an unrecognised message is passed through exactly as it arrived.

But it has never fired. Against Visual Studio 2026, Fold(Fold(1)) evaluates to 153 — this evaluator does not refuse nested calls outright, so the matcher is written against wording I have not seen. The wording quoted in this issue must come from a narrower case: a particular engine, or a particular kind of call.

If you hit it again, the exact text of the refusal and roughly what the call looked like would be enough to finish this. Everything else from that round is closed.