Both compile-let (regular + dict-destructure bindings) and compile-letrec
(named-let / letrec slot-init + value-assign) emitted `<value>; LOCAL_SET slot`
with NO POP. Slots are pre-allocated and LOCAL_SET peeks (doesn't pop), so each
binding value was left as stack residue. In TAIL position this was masked
(OP_TAIL_CALL resets sp to frame.base); in NON-TAIL position the residue leaked
to the enclosing frame, so the caller popped the wrong value ("not callable: 7",
"rest: 1 list arg", "first: expected list, got true") under the serving JIT.
Fix: emit POP (op 5) after each binding's LOCAL_SET. Broad correctness win for
any let/letrec in non-tail position under JIT (and the precondition for landing
the HO-loop desugar, which builds on named-let recur).
Ported from loops/sx-vm-extensions 3126d728 + 41d46f1b (compiler.sx hunks only;
spike commit and worktree .mcp.json/lock noise excluded). --jit conformance in
the source branch: 4842/1102 -> 4847/1097 (+5 fixed, zero regressions).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
giles
be071d5631