add dev repo for Coq beta

Author: yforster

.github/workflows/build.yml

@@ -27,6 +27,7 @@ jobs:
           fetch-depth: 1
 
       - run: opam repo add coq-released https://coq.inria.fr/opam/released
+      - run: opam repo add coq-core-dev https://coq.inria.fr/opam/core-dev
       - run: opam install . --deps-only --with-doc --with-test
 
       - run: opam exec -- make -j 2 all

opam

@@ -12,7 +12,7 @@ build: [make "-j%{jobs}%"]
 install: [make "install"]
 depends: [
   "ocaml"
-  "coq" { >= "8.13" & < "8.14~" }
+  "coq" { = "8.13+beta1" }
 ]
 synopsis: "Smpl: An Extensible Tactic for Coq"
 description: """