diff --git a/pkgs/development/python-modules/unittest2/collections-compat.patch b/pkgs/development/python-modules/unittest2/collections-compat.patch
new file mode 100644
index 000000000000..350c9d716783
--- /dev/null
+++ b/pkgs/development/python-modules/unittest2/collections-compat.patch
@@ -0,0 +1,19 @@
+diff --git a/unittest2/compatibility.py b/unittest2/compatibility.py
+index 9e5f1a5..473957c 100644
+--- a/unittest2/compatibility.py
++++ b/unittest2/compatibility.py
+@@ -1,4 +1,5 @@
+ import collections
++import collections.abc
+ import os
+ import sys
+ 
+@@ -140,7 +141,7 @@ except ImportError:
+ ###  ChainMap (helper for configparser and string.Template)
+ ########################################################################
+ 
+-class ChainMap(collections.MutableMapping):
++class ChainMap(collections.abc.MutableMapping):
+     ''' A ChainMap groups multiple dicts (or other mappings) together
+     to create a single, updateable view.
+ 
diff --git a/pkgs/development/python-modules/unittest2/default.nix b/pkgs/development/python-modules/unittest2/default.nix
index e044176242d5..786b8996f83b 100644
--- a/pkgs/development/python-modules/unittest2/default.nix
+++ b/pkgs/development/python-modules/unittest2/default.nix
@@ -15,6 +15,10 @@ buildPythonPackage rec {
     sha256 = "0y855kmx7a8rnf81d3lh5lyxai1908xjp0laf4glwa4c8472m212";
   };
 
+  patches = lib.optionals (pythonAtLeast "3.7") [
+    ./collections-compat.patch
+  ];
+
   propagatedBuildInputs = [ six traceback2 ];
 
   # 1.0.0 and up create a circle dependency with traceback2/pbr
@@ -34,7 +38,5 @@ buildPythonPackage rec {
     description = "A backport of the new features added to the unittest testing framework";
     homepage = "https://pypi.org/project/unittest2/";
     license = licenses.bsd0;
-    # AttributeError: module 'collections' has no attribute 'MutableMapping'
-    broken = pythonAtLeast "3.10";
   };
 }
diff --git a/pkgs/tools/compression/zfp/default.nix b/pkgs/tools/compression/zfp/default.nix
index c46c58e7b404..0b337f613366 100644
--- a/pkgs/tools/compression/zfp/default.nix
+++ b/pkgs/tools/compression/zfp/default.nix
@@ -1,4 +1,4 @@
-{ cmake, cudatoolkit, fetchFromGitHub, gfortran, lib, llvmPackages, pythonPackages, stdenv, targetPlatform
+{ cmake, cudatoolkit, fetchFromGitHub, gfortran, lib, llvmPackages, python3Packages, stdenv, targetPlatform
 , enableCfp ? true
 , enableCuda ? false
 , enableExamples ? true
@@ -23,7 +23,7 @@ stdenv.mkDerivation rec {
   buildInputs = lib.optional enableCuda cudatoolkit
     ++ lib.optional enableFortran gfortran
     ++ lib.optional enableOpenMP llvmPackages.openmp
-    ++ lib.optionals enablePython [ pythonPackages.cython pythonPackages.numpy pythonPackages.python ];
+    ++ lib.optionals enablePython (with python3Packages; [ cython numpy python ]);
 
   cmakeFlags = [
     # More tests not enabled by default