Make lib imports in overlay explicit

To support the new instrumentation for HWC it would be useful to already
build nOS-V with PAPI support enabled. The enablePapi switch allows it
to be disabled with `nosv.override { enablePapi = false; }`.

Reviewed-by: Aleix Roca Nonell <aleix.rocanonell@bsc.es>
Tested-by: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>

overlay.nix

@@ -1,15 +1,19 @@
 final: /* Future last stage */
 prev:  /* Previous stage */
 
-with final.lib;
-
 let
-  callPackage = final.callPackage;
+  inherit (prev.lib) collect isDerivation mapAttrs;
+
+  inherit (final) callPackage;
 
   mkDeps = name: pkgs: final.runCommand name { }
     "printf '%s\n' ${toString (collect (x: x ? outPath) pkgs)} > $out";
 
-  bscPkgs = {
+  mkStrict = drv: if (isDerivation drv && drv ? overrideAttrs && !(drv ? strictDeps))
+    then drv.overrideAttrs { strictDeps = true; }
+    else drv;
+
+  bscPkgs = mapAttrs (_: mkStrict) {
     bench6 = callPackage ./pkgs/bench6/default.nix { };
     bigotes = callPackage ./pkgs/bigotes/default.nix { };
     clangOmpss2 = callPackage ./pkgs/llvm-ompss2/default.nix { };

pkgs/nosv/default.nix

@@ -6,6 +6,8 @@
 , pkg-config
 , numactl
 , hwloc
+, papi
+, enablePapi ? true
 , cacheline ? 64 # bits
 , ovni ? null
 , useGit ? false
@@ -56,5 +58,5 @@ in
       numactl
       hwloc
       ovni
-    ];
+    ] ++ lib.optionals enablePapi [ papi ];
   }