Split the opam package into 3 packages and let opam do the installation instead of dune.

Makefile

@@ -287,12 +287,11 @@ export:
 # The following command should have been run once:
 #   opam publish repo add opam-coq-archive coq/opam-coq-archive
 
-# The package name.
-THIS     := menhir
-THAT     := coq-menhirlib
+# An abbreviation.
+COQLIB   := coq-menhirlib
 
 # Menhir's repository URL (https).
-REPO     := https://gitlab.inria.fr/fpottier/$(THIS)
+REPO     := https://gitlab.inria.fr/fpottier/menhir
 
 # The archive URL (https).
 ARCHIVE  := $(REPO)/repository/$(DATE)/archive.tar.gz
@@ -304,18 +303,19 @@ COQ_MENHIRLIB_PUBLISH_OPTIONS := \
 
 .PHONY: opam
 opam:
-# Publish an opam description for menhir.
-	@ opam publish -v $(DATE) $(THIS).opam $(ARCHIVE)
+# Publish opam descriptions for menhirLib, menhirSdk, menhir.
+	@ opam publish -v $(DATE) menhirLib.opam menhirSdk.opam menhir.opam $(ARCHIVE)
 # Patch coq-menhirlib.opam.
 # We replace the string DATEDASH with $(DATEDASH).
 # We replace the string DATE with $(DATE).
-	@ cat $(THAT).opam \
+	@ cat $(COQLIB).opam \
 	  | sed -e 's/DATEDASH/$(DATEDASH)/g' \
 	  | sed -e 's/DATE/$(DATE)/g' \
-	  > $(THAT).patched.opam
+	  > $(COQLIB).patched.opam
 # Publish an opam description for coq-menhirlib.
-	@ opam publish -v $(DATE) $(COQ_MENHIRLIB_PUBLISH_OPTIONS) $(THAT).patched.opam $(ARCHIVE)
-	@ rm $(THAT).patched.opam
+	@ opam publish -v $(DATE) $(COQ_MENHIRLIB_PUBLISH_OPTIONS) \
+	    $(COQLIB).patched.opam $(ARCHIVE)
+	@ rm $(COQLIB).patched.opam
 
 # -------------------------------------------------------------------------
 
@@ -323,11 +323,13 @@ opam:
 
 .PHONY: pin
 pin:
-	opam pin add menhir.dev .
+	opam pin --yes add menhirLib.dev . && \
+	opam pin --yes add menhirSdk.dev . && \
+	opam pin --yes add menhir.dev .
 
 .PHONY: unpin
 unpin:
-	opam pin remove menhir
+	opam pin --yes remove menhirLib menhirSdk menhir
 
 # -------------------------------------------------------------------------
 

menhir.opam

-name: "menhir"
 opam-version: "2.0"
 maintainer: "francois.pottier@inria.fr"
 authors: [
@@ -9,13 +8,12 @@ homepage: "http://gitlab.inria.fr/fpottier/menhir"
 dev-repo: "git+https://gitlab.inria.fr/fpottier/menhir.git"
 bug-reports: "menhir@inria.fr"
 build: [
-  ["dune" "build" "@install" "-j" jobs "--profile=release"]
-]
-install: [
-  ["dune" "install" "-j" jobs]
+  ["dune" "build" "-p" name "-j" jobs]
 ]
 depends: [
   "ocaml" {>= "4.02.3"}
   "dune" {>= "2.0.0"}
+  "menhirLib" {= version}
+  "menhirSdk" {= version}
 ]
 synopsis: "An LR(1) parser generator"

menhirLib.opam

+opam-version: "2.0"
+maintainer: "francois.pottier@inria.fr"
+authors: [
+  "François Pottier <francois.pottier@inria.fr>"
+  "Yann Régis-Gianas <yrg@pps.univ-paris-diderot.fr>"
+]
+homepage: "http://gitlab.inria.fr/fpottier/menhir"
+dev-repo: "git+https://gitlab.inria.fr/fpottier/menhir.git"
+bug-reports: "menhir@inria.fr"
+build: [
+  ["dune" "build" "-p" name "-j" jobs]
+]
+depends: [
+  "ocaml" {>= "4.02.3"}
+  "dune" {>= "2.0.0"}
+]
+synopsis: "Runtime support library for parsers generated by Menhir"

menhirSdk.opam

+opam-version: "2.0"
+maintainer: "francois.pottier@inria.fr"
+authors: [
+  "François Pottier <francois.pottier@inria.fr>"
+  "Yann Régis-Gianas <yrg@pps.univ-paris-diderot.fr>"
+]
+homepage: "http://gitlab.inria.fr/fpottier/menhir"
+dev-repo: "git+https://gitlab.inria.fr/fpottier/menhir.git"
+bug-reports: "menhir@inria.fr"
+build: [
+  ["dune" "build" "-p" name "-j" jobs]
+]
+depends: [
+  "ocaml" {>= "4.02.3"}
+  "dune" {>= "2.0.0"}
+]
+synopsis: "Compile-time library for auxiliary tools related to Menhir"