coq_8_6: 8.6 is now default, 8.4 optional, updated mathcomp/ssreflect

Addresses #14829

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

@@ -1,24 +1,39 @@
-{ callPackage, coq, fetchurl }:
+{ callPackage, fetchurl, coq }:
 
-let src = 
-  if coq.coq-version == "8.4" then
-
-    fetchurl {
-      url = http://ssr.msr-inria.inria.fr/FTP/mathcomp-1.6.tar.gz;
-      sha256 = "0adr556032r1jkvphbpfvrrv041qk0yqb7a1xnbam52ji0mdl2w8";
-    }
-
-  else if coq.coq-version == "8.5" then
-
-    fetchurl {
-      url = http://ssr.msr-inria.inria.fr/FTP/mathcomp-1.6.tar.gz;
-      sha256 = "0adr556032r1jkvphbpfvrrv041qk0yqb7a1xnbam52ji0mdl2w8";
-    }
-
-  else throw "No mathcomp package for Coq version ${coq.coq-version}";
-
-in
+if coq.coq-version == "8.4" then
 
 callPackage ./generic.nix {
-  inherit src;
+
+  name = "coq-mathcomp-1.6-${coq.coq-version}";
+  src = fetchurl {
+    url = http://ssr.msr-inria.inria.fr/FTP/mathcomp-1.6.tar.gz;
+    sha256 = "0adr556032r1jkvphbpfvrrv041qk0yqb7a1xnbam52ji0mdl2w8";
+  };
+
 }
+
+else if coq.coq-version == "8.5" then
+
+callPackage ./generic.nix {
+
+  name = "coq-mathcomp-1.6-${coq.coq-version}";
+  src = fetchurl {
+    url = http://ssr.msr-inria.inria.fr/FTP/mathcomp-1.6.tar.gz;
+    sha256 = "0adr556032r1jkvphbpfvrrv041qk0yqb7a1xnbam52ji0mdl2w8";
+  };
+
+}
+
+else if coq.coq-version == "8.6" then
+
+callPackage ./generic.nix {
+
+  name = "coq-mathcomp-1.6.1-${coq.coq-version}";
+  src = fetchurl {
+    url = https://github.com/math-comp/math-comp/archive/mathcomp-1.6.1.tar.gz;
+    sha256 = "1j9ylggjzrxz1i2hdl2yhsvmvy5z6l4rprwx7604401080p5sgjw";
+  };
+
+}
+
+else throw "No ssreflect package for Coq version ${coq.coq-version}"

pkgs/development/coq-modules/mathcomp/generic.nix

@@ -1,12 +1,11 @@
 { stdenv, fetchurl, coq, ssreflect, ncurses, which
 , graphviz, ocamlPackages, withDoc ? false
-, src
+, src, name
 }:
 
 stdenv.mkDerivation {
 
-  name = "coq-mathcomp-1.6-${coq.coq-version}";
-
+  inherit name;
   inherit src;
 
   nativeBuildInputs = stdenv.lib.optionals withDoc [ graphviz ];