Further changes

coverage.nix

@@ -0,0 +1,35 @@
+{ lib
+, releaseTools
+, nix
+, stdenv
+}:
+
+let
+  inherit (nix) version;
+
+in
+
+releaseTools.coverageAnalysis {
+  name = "nix-coverage-${version}";
+
+  inherit (nix)
+    src
+    configureFlags
+    nativeBuildInputs
+    buildInputs
+    #checkInputs
+    ;
+
+  enableParallelBuilding = true;
+
+  dontInstall = false;
+
+  doInstallCheck = true;
+  installCheckTarget = "installcheck"; # work around buggy detection in stdenv
+
+  lcovFilter = [ "*/boost/*" "*-tab.*" ];
+
+  hardeningDisable = ["fortify"];
+
+  NIX_CFLAGS_COMPILE = "-DCOVERAGE=1";
+}