openssh: build with correct passwd path

pkgs/tools/networking/openssh/common.nix

@@ -32,6 +32,7 @@
 , withPAM ? stdenv.hostPlatform.isLinux
 , dsaKeysSupport ? false
 , linkOpenssl ? true
+, isNixos ? stdenv.hostPlatform.isLinux
 }:
 
 stdenv.mkDerivation {
@@ -75,6 +76,12 @@ stdenv.mkDerivation {
     unset LD
   '';
 
+  env = lib.optionalAttrs isNixos {
+    # openssh calls passwd to allow the user to reset an expired password, but nixos
+    # doesn't ship it at /usr/bin/passwd.
+    PATH_PASSWD_PROG = "/run/wrappers/bin/passwd";
+  };
+
   # I set --disable-strip because later we strip anyway. And it fails to strip
   # properly when cross building.
   configureFlags = [