pythonPackage.celery: fix tests

(cherry picked from commit 47a3a11)

pkgs/development/python-modules/celery/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi, iana-etc, libredirect
+{ lib, buildPythonPackage, fetchPypi, libredirect
 , case, pytest, boto3, moto, kombu, billiard, pytz, anyjson, amqp, eventlet
 }:
 
@@ -17,19 +17,17 @@ buildPythonPackage rec {
       --replace "pytest>=4.3.1,<4.4.0" pytest
   '';
 
-  # make /etc/protocols accessible to fix socket.getprotobyname('tcp') in sandbox
-  preCheck = stdenv.lib.optionalString stdenv.isLinux ''
-    export NIX_REDIRECTS=/etc/protocols=${iana-etc}/etc/protocols \
-      LD_PRELOAD=${libredirect}/lib/libredirect.so
-  '';
-  postCheck = stdenv.lib.optionalString stdenv.isLinux ''
-    unset NIX_REDIRECTS LD_PRELOAD
+  # ignore test that's incompatible with pytest5
+  # test_eventlet touches network
+  checkPhase = ''
+    pytest -k 'not restore_current_app_fallback' \
+      --ignore=t/unit/concurrency/test_eventlet.py
   '';
 
   checkInputs = [ case pytest boto3 moto ];
   propagatedBuildInputs = [ kombu billiard pytz anyjson amqp eventlet ];
 
-  meta = with stdenv.lib; {
+  meta = with lib; {
     homepage = https://github.com/celery/celery/;
     description = "Distributed task queue";
     license = licenses.bsd3;