stdenv/darwin: Ignore version override warning

I don't suppose we need to set `src`, the suggestion of the warning.
This is presumably just to signify that it's not the final build
(not *really*) a version.

pkgs/stdenv/darwin/default.nix

@@ -439,6 +439,7 @@ assert bootstrapTools.passthru.isFromBootstrapFiles or false; # sanity check
               (superDarwin.binutils-unwrapped.override { enableManpages = false; }).overrideAttrs
                 (old: {
                   version = "boot";
+                  __intentionallyOverridingVersion = true; # to avoid a warning suggesting to provide src
                   passthru = (old.passthru or { }) // {
                     isFromBootstrapFiles = true;
                   };