Keeps older CoLoR available for older Coq

pkgs/development/coq-modules/CoLoR/default.nix

@@ -1,13 +1,34 @@
 { stdenv, fetchFromGitHub, coq, bignums }:
 
+let
+  coqVersions = {
+    "8.6" = "1.4.0";
+    "8.7" = "1.4.0";
+    "8.8" = "1.6.0";
+    "8.9" = "1.6.0";
+  };
+  params = {
+    "1.4.0" = {
+      version = "1.4.0";
+      rev = "168c6b86c7d3f87ee51791f795a8828b1521589a";
+      sha256 = "1d2whsgs3kcg5wgampd6yaqagcpmzhgb6a0hp6qn4lbimck5dfmm";
+    };
+    "1.6.0" = {
+      version = "1.6.0";
+      rev = "328aa06270584b578edc0d2925e773cced4f14c8";
+      sha256 = "07sy9kw1qlynsqy251adgi8b3hghrc9xxl2rid6c82mxfsp329sd";
+    };
+  };
+  param = params.${coqVersions.${coq.coq-version}};
+in
+
 stdenv.mkDerivation {
-  name = "coq${coq.coq-version}-CoLoR-1.6.0";
+  name = "coq${coq.coq-version}-CoLoR-${param.version}";
 
   src = fetchFromGitHub {
     owner = "fblanqui";
     repo = "color";
-    rev = "328aa06270584b578edc0d2925e773cced4f14c8";
-    sha256 = "07sy9kw1qlynsqy251adgi8b3hghrc9xxl2rid6c82mxfsp329sd";
+    inherit (param) rev sha256;
   };
 
   buildInputs = [ coq bignums ];
@@ -17,7 +38,7 @@ stdenv.mkDerivation {
     make -f Makefile.coq COQLIB=$out/lib/coq/${coq.coq-version}/ install
   '';
 
-  meta = with stdenv.lib ; {
+  meta = with stdenv.lib; {
     homepage = http://color.inria.fr/;
     description = "CoLoR is a library of formal mathematical definitions and proofs of theorems on rewriting theory and termination whose correctness has been mechanically checked by the Coq proof assistant.";
     maintainers = with maintainers; [ jpas jwiegley ];
@@ -25,6 +46,6 @@ stdenv.mkDerivation {
   };
 
   passthru = {
-    compatibleCoqVersions = v: builtins.elem v [ "8.6" "8.7" "8.8" "8.9" ];
+    compatibleCoqVersions = v: builtins.hasAttr v coqVersions;
   };
 }