Fix dune-dbg inside emacs with dune >= 3

cf ocaml/dune#4680

dev/dune-dbg.in

@@ -1,29 +1,38 @@
 #!/usr/bin/env bash
-
 # Run in a proper install dune env.
-case $1 in
-    coqchk)
-        shift
-        exe=_build/default/checker/coqchk.bc
-        ;;
-    coqide)
-        shift
-        exe=_build/default/ide/coqide/coqide_main.bc
-        ;;
-    coqc)
-        shift
-        exe=_build/default/topbin/coqc_bin.bc
-        ;;
-    coqtop)
-        shift
-        exe=_build/default/topbin/coqtop_byte_bin.bc
-        ;;
-    *)
-        echo "First argument must be one of {coqc,coqtop,coqchk,coqide}"
-        exit 1
-        ;;
-esac
 
-emacs="${INSIDE_EMACS:+-emacs}"
+opts=()
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        -emacs)
+            shift
+            opts+=("-emacs")
+            ;;
+        coqchk)
+            shift
+            exe=_build/default/checker/coqchk.bc
+            break
+            ;;
+        coqide)
+            shift
+            exe=_build/default/ide/coqide/coqide_main.bc
+            break
+            ;;
+        coqc)
+            shift
+            exe=_build/default/topbin/coqc_bin.bc
+            break
+            ;;
+        coqtop)
+            shift
+            exe=_build/default/topbin/coqtop_byte_bin.bc
+            break
+            ;;
+        *)
+            echo "usage: dune exec -- dev/dune-dbg [-emacs] {coqchk|coqide|coqc|coqtop} coqargs"
+            exit 1
+            ;;
+    esac
+done
 
-ocamldebug $emacs $(ocamlfind query -recursive -i-format coq-core.top_printers) -I +threads -I dev $exe "$@"
+ocamldebug "${opts[@]}" $(ocamlfind query -recursive -i-format coq-core.top_printers) -I +threads -I dev $exe "$@"

dev/tools/coqdev.el

@@ -87,7 +87,7 @@ Note that this function is executed before _Coqproject is read if it exists."
       (setq-local coq-prog-name (concat dir "_build/default/dev/shim/coqtop-prelude")))))
 (add-hook 'hack-local-variables-hook #'coqdev-setup-proofgeneral)
 
-(defvar coqdev-ocamldebug-command "dune exec -- dev/dune-dbg coqc /tmp/foo.v"
+(defvar coqdev-ocamldebug-command "dune exec -- dev/dune-dbg -emacs coqc /tmp/foo.v"
   "Command run by `coqdev-ocamldebug'")
 
 (declare-function comint-check-proc "comint")