From b3148b97313ffde81e9b4c65fabd2c58a093f25b Mon Sep 17 00:00:00 2001
From: Frederik Rietdijk <fridh@fridh.nl>
Date: Sun, 14 Mar 2021 09:30:49 +0100
Subject: [PATCH] pythonPackages.pytestCheckHook_6_1: only override for Python
 3

---
 pkgs/top-level/python-packages.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 6c4c0738a6d..e3264e83669 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -124,7 +124,15 @@ in {
     venvShellHook
     wheelUnpackHook;
 
-  pytestCheckHook_6_1 = self.pytestCheckHook.override { pytest = self.pytest_6_1; };
+  # Not all packages are compatible with the latest pytest yet.
+  # We need to override the hook to select an older pytest, however,
+  # it should not override the version of pytest that is used for say
+  # Python 2. This is an ugly hack that is needed now because the hook
+  # propagates the package.
+  pytestCheckHook_6_1 = if isPy3k then
+    self.pytestCheckHook.override { pytest = self.pytest_6_1; }
+  else
+    self.pytestCheckHook;
 
   # helpers