In 8.18, MetaCoq Run sometimes returns an anomaly when running incorrectly typed code.

[DeLectionnes]

In 8.18, MetaCoq Run sends an anomaly if you Run a piece of code that is not typed correctly, and that the Coq typechecker rejects.

In 8.16, it only sends an error, not an anomaly.

This happens with the version 1.2.1+8.18 installed via opam.

From MetaCoq.Utils Require Import utils.
From MetaCoq.Template Require Import All.
Import MCMonadNotation.


(*Exemple with a typing error*)
Definition ident_term (a : term) : term := a.

Definition quote_inductive {X}(inductive:X): TemplateMonad _ := 
  quote <- tmQuote inductive;;
  tmReturn quote.

Inductive tm : Set := .

Definition d1 : TemplateMonad unit.
Fail refine (
    quote  <- quote_inductive tm;;
    constructor <- ident_term quote;;
    tmPrint constructor)
.
(*The command has indeed failed with message:
In environment
quote : term
Unable to unify "term" with "TemplateMonad ?Goal2".
(while solving unification constraints, see flag "Solve Unification Constraints")*)
Abort.

Fail MetaCoq Run(
    quote  <- quote_inductive tm;;
    constructor <- ident_term quote;;
    tmPrint constructor)
.
(*Error: Anomaly "File "kernel/constr.ml", line 1485, characters 26-32: Assertion failed."
Please report at http://coq.inria.fr/bugs/.*)
``

[mattam82]

Fixed in #1068 and released in 1.3.1 versions (soon in opam)