nix-serve: set PATH

joachifm: also set `dontBuild = true`; `false` doesn't make any sense if
the intent is to skip the build phase.

Closes #16221

pkgs/tools/package-management/nix-serve/default.nix

···
-{ lib, stdenv, fetchFromGitHub, perl, nix, perlPackages }:
+{ stdenv, fetchFromGitHub,
+  bzip2, nix, perl, perlPackages,
+}:
 
-let rev = "7e09caa2a7a435aeb2cd5446aa590d6f9ae1699d"; in
+with stdenv.lib;
+
+let
+  rev = "7e09caa2a7a435aeb2cd5446aa590d6f9ae1699d";
+  sha256 = "0mjzsiknln3isdri9004wwjjjpak5fj8ncizyncf5jv7g4m4q1pj";
+in
 
 stdenv.mkDerivation rec {
-  name = "nix-serve-0.2-${lib.substring 0 7 rev}";
+  name = "nix-serve-0.2-${substring 0 7 rev}";
 
   src = fetchFromGitHub {
     owner = "edolstra";
     repo = "nix-serve";
-    inherit rev;
-    sha256 = "0mjzsiknln3isdri9004wwjjjpak5fj8ncizyncf5jv7g4m4q1pj";
+    inherit rev sha256;
   };
 
-  buildInputs = [ perl nix ]
+  buildInputs = [ bzip2 perl nix ]
     ++ (with perlPackages; [ DBI DBDSQLite Plack Starman ]);
 
-  dontBuild = false;
+  dontBuild = true;
 
-  # FIXME: unfortunate cut&paste.
   installPhase = ''
     mkdir -p $out/libexec/nix-serve
     cp nix-serve.psgi $out/libexec/nix-serve/nix-serve.psgi
···
     mkdir -p $out/bin
     cat > $out/bin/nix-serve <<EOF
     #! ${stdenv.shell}
-    PERL5LIB=$PERL5LIB exec ${perlPackages.Starman}/bin/starman $out/libexec/nix-serve/nix-serve.psgi "\$@"
+    PATH=${makeBinPath [ bzip2 nix ]}:\$PATH PERL5LIB=$PERL5LIB exec ${perlPackages.Starman}/bin/starman $out/libexec/nix-serve/nix-serve.psgi "\$@"
     EOF
     chmod +x $out/bin/nix-serve
   '';