openssh: put tests into passthru

openssh tests are very slow (they take ~30 mins because they are not
parallelized). This makes rebuilding (esp. after changes e.g. to
systemd) painful. Putting the tests into a separate derivation solves
this without losing any testing capability.

Debian does the same: https://packages.debian.org/sid/openssh-tests

pkgs/tools/networking/openssh/common.nix

@@ -33,7 +33,7 @@
 , linkOpenssl ? true
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation (finalAttrs: {
  inherit pname version src;
 
  patches = [
@@ -100,7 +100,7 @@ stdenv.mkDerivation {
 
  hardeningEnable = [ "pie" ];
 
- doCheck = true;
+ doCheck = false;
  enableParallelChecking = false;
  nativeCheckInputs = [ openssl ] ++ lib.optional (!stdenv.isDarwin) hostname;
  preCheck = lib.optionalString (stdenv.hostPlatform == stdenv.buildPlatform) ''
@@ -167,6 +167,9 @@ stdenv.mkDerivation {
  ];
 
  passthru.tests = {
+ openssh = finalAttrs.finalPackage.overrideAttrs (_: {
+ doCheck = true;
+ });
  borgbackup-integration = nixosTests.borgbackup;
  };
 
@@ -179,4 +182,4 @@ stdenv.mkDerivation {
  maintainers = (extraMeta.maintainers or []) ++ (with maintainers; [ eelco aneeshusa ]);
  mainProgram = "ssh";
  } // extraMeta;
-}
+})