From 10d7bfedaeb72325b5628678c056487319aae931 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9o=20Zimmermann?=
 <theo.zimmermann@univ-paris-diderot.fr>
Date: Fri, 19 Apr 2019 14:54:27 +0200
Subject: [PATCH] ocaml-ng.ocamlPackages_4_07.seq: dummy package with just a
 META file

Imitate opam which installs the real seq package only for OCaml < 4.07 and only a META file for OCaml >= 4.07.
---
 .../development/ocaml-modules/seq/default.nix | 39 +++++++++++++------
 .../ocaml-modules/seq/src-base/META           |  4 ++
 2 files changed, 32 insertions(+), 11 deletions(-)
 create mode 100644 pkgs/development/ocaml-modules/seq/src-base/META

diff --git a/pkgs/development/ocaml-modules/seq/default.nix b/pkgs/development/ocaml-modules/seq/default.nix
index f4918b420c4..7a50d1517db 100644
--- a/pkgs/development/ocaml-modules/seq/default.nix
+++ b/pkgs/development/ocaml-modules/seq/default.nix
@@ -1,13 +1,22 @@
 { stdenv, fetchFromGitHub, ocaml, findlib, ocamlbuild }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation ({
   version = "0.1";
-  name = "ocaml${ocaml.version}-seq-${version}";
+  name = "ocaml${ocaml.version}-seq-0.1";
+
+  meta = {
+    license = stdenv.lib.licenses.lgpl21;
+    maintainers = [ stdenv.lib.maintainers.vbgl ];
+    homepage = "https://github.com/c-cube/seq";
+    inherit (ocaml.meta) platforms;
+  };
+
+} // (if stdenv.lib.versionOlder ocaml.version "4.07" then {
 
   src = fetchFromGitHub {
     owner = "c-cube";
     repo = "seq";
-    rev = version;
+    rev = "0.1";
     sha256 = "1cjpsc7q76yfgq9iyvswxgic4kfq2vcqdlmxjdjgd4lx87zvcwrv";
   };
 
@@ -15,11 +24,19 @@ stdenv.mkDerivation rec {
 
   createFindlibDestdir = true;
 
-  meta = {
-    description = "Compatibility package for OCaml’s standard iterator type starting from 4.07";
-    license = stdenv.lib.licenses.lgpl21;
-    maintainers = [ stdenv.lib.maintainers.vbgl ];
-    inherit (src.meta) homepage;
-    inherit (ocaml.meta) platforms;
-  };
-}
+  meta.description = "Compatibility package for OCaml’s standard iterator type starting from 4.07";
+
+} else {
+
+  src = ./src-base;
+
+  dontBuild = true;
+
+  installPhase = ''
+    mkdir -p $out/lib/ocaml/${ocaml.version}/site-lib/seq
+    cp META $out/lib/ocaml/${ocaml.version}/site-lib/seq
+  '';
+
+  meta.description = "dummy backward-compatibility package for iterators";
+
+}))
diff --git a/pkgs/development/ocaml-modules/seq/src-base/META b/pkgs/development/ocaml-modules/seq/src-base/META
new file mode 100644
index 00000000000..06b95eff3f8
--- /dev/null
+++ b/pkgs/development/ocaml-modules/seq/src-base/META
@@ -0,0 +1,4 @@
+name="seq"
+version="[distributed with OCaml 4.07 or above]"
+description="dummy backward-compatibility package for iterators"
+requires=""