perl: fix build with libxcrypt

pkgs/development/interpreters/perl/default.nix

···
 { config, lib, stdenv, fetchurl, fetchFromGitHub, pkgs, buildPackages
 , callPackage
 , enableThreading ? true, coreutils, makeWrapper
-, enableCrypt ? true
+, enableCrypt ? true, libxcrypt ? null
 , zlib
 }:
+
+assert (enableCrypt -> (libxcrypt != null));
 
 # Note: this package is used for bootstrapping fetchurl, and thus
 # cannot use fetchpatch! All mutable patches (generated by GitHub or
···
     outputs = [ "out" "man" "devdoc" ] ++
       optional crossCompiling "mini";
     setOutputFlags = false;
+
+    propagatedBuildInputs = lib.optional enableCrypt libxcrypt;
 
     disallowedReferences = [ stdenv.cc ];
 

pkgs/stdenv/linux/default.nix

···
       # This is not an issue for the final stdenv, because this perl
       # won't be included in the final stdenv and won't be exported to
       # top-level pkgs as an override either.
-      perl = super.perl.override { enableThreading = false; };
+      perl = super.perl.override { enableThreading = false; enableCrypt = false; };
     };
   })
 

pkgs/top-level/all-packages.nix

···
   libx86 = callPackage ../development/libraries/libx86 {};
 
   libxcrypt = callPackage ../development/libraries/libxcrypt {
-    perl = perl.override { enableCrypt = false; };
+    fetchurl = stdenv.fetchurlBoot;
+    perl = perl.override {
+      enableCrypt = false;
+      fetchurl = stdenv.fetchurlBoot;
+    };
   };
 
   libxdg_basedir = callPackage ../development/libraries/libxdg-basedir { };