coq-modules: add default to fix eval

We don’t want these to not even evaluate, otherwise we won’t know why
they’re broken. For now, I’ve left these as the latest version for a
default. In the future, maybe we should be smarter about choosing these.

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

@@ -28,7 +28,7 @@ let params =
       propagatedBuildInputs = [ coq-ext-lib simple-io ];
     };
   };
-  param = params."${coq.coq-version}";
+  param = params."${coq.coq-version}" or params."8.8";
 in
 
 stdenv.mkDerivation rec {

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

@@ -20,7 +20,7 @@ let params =
       sha256 = "0l9885nxy0n955fj1gnijlxl55lyxiv9yjfmz8hmfrn9hl8vv1m2";
     };
   };
-  param = params."${coq.coq-version}";
+  param = params."${coq.coq-version}" or params."8.8";
 in
 
 stdenv.mkDerivation rec {

pkgs/development/coq-modules/category-theory/default.nix

@@ -18,7 +18,7 @@ let
     "8.7" = v20180709;
     "8.8" = v20181016;
   };
-  param = params."${coq.coq-version}";
+  param = params."${coq.coq-version}" or params."8.8";
 in
 
 stdenv.mkDerivation rec {

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

@@ -26,7 +26,7 @@ let params =
       sha256 = "09dq1vvshhlhgjccrhqgbhnq2hrys15xryfszqq11rzpgvl2zgdv";
     };
   };
-  param = params."${coq.coq-version}";
+  param = params."${coq.coq-version}" or params."8.8";
 in
 
 stdenv.mkDerivation rec {

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

@@ -14,7 +14,7 @@ let params =
     "8.8" = v_8_8;
     "8.9" = v_8_8;
     };
-  param = params."${coq.coq-version}"
+  param = params."${coq.coq-version}" or params."8.9"
 ; in
 
 stdenv.mkDerivation rec {

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

@@ -22,7 +22,7 @@ let params = {
     sha256 = "0qvar8gfbrcs9fmvkph5asqz4l5fi63caykx3bsn8zf0xllkwv0n";
   };
 };
-param = params."${coq.coq-version}";
+param = params."${coq.coq-version}" or params."8.8";
 in
 
 stdenv.mkDerivation {

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

@@ -20,7 +20,7 @@ let
       sha256 = "0dd7zd5j2sv5cw3mfwg33ss2vcj634q3qykakc41sv7f3rfgqfnn";
     };
   };
-  param = params."${coq.coq-version}";
+  param = params."${coq.coq-version}" or params."8.8";
 in
 
 stdenv.mkDerivation rec {