test with name mangling on CI

.gitlab-ci.yml

@@ -31,6 +31,7 @@ build-coq.dev:
   <<: *template
   variables:
     OPAM_PINS: "coq version dev"
+    MANGLE_NAMES: "1"
     CI_COQCHK: "1"
 
 build-coq.8.12.0:

tests/telescopes.v

 From stdpp Require Import tactics telescopes.
 
+Local Unset Mangle Names. (* for stable goal printing *)
+
 Section accessor.
 (* This is like Iris' accessors, but in Prop.  Just to play with telescopes. *)
 Definition accessor {X : tele} (α β γ : X → Prop) : Prop :=