diff --git a/pkgs/applications/video/minitube/default.nix b/pkgs/applications/video/minitube/default.nix
index a1ccc353d56..84b5e2a1d73 100644
--- a/pkgs/applications/video/minitube/default.nix
+++ b/pkgs/applications/video/minitube/default.nix
@@ -16,12 +16,11 @@ mkDerivation rec {
     fetchSubmodules = true;
   };
 
-  buildInputs = [ phonon phonon-backend-vlc qtbase qtdeclarative qtx11extras mpv ];
   nativeBuildInputs = [ qmake qttools ];
 
-  qmakeFlags = [ "DEFINES+=APP_GOOGLE_API_KEY=${withAPIKey}" ];
+  buildInputs = [ phonon phonon-backend-vlc qtbase qtdeclarative qtx11extras mpv ];
 
-  enableParallelBuilding = true;
+  qmakeFlags = [ "DEFINES+=APP_GOOGLE_API_KEY=${withAPIKey}" ];
 
   meta = with lib; {
     description = "Stand-alone YouTube video player";
diff --git a/pkgs/development/libraries/mauikit/default.nix b/pkgs/development/libraries/mauikit/default.nix
index 0ec814b7164..38e938080ba 100644
--- a/pkgs/development/libraries/mauikit/default.nix
+++ b/pkgs/development/libraries/mauikit/default.nix
@@ -37,6 +37,6 @@ mkDerivation rec {
     description = "Free and modular front-end framework for developing fast and compelling user experiences";
     license = licenses.lgpl2Plus;
     maintainers = with maintainers; [ dotlambda ];
-    broken = lib.versionOlder qtbase.version "5.14.0";
+    broken = versionOlder qtbase.version "5.14.0";
   };
 }
diff --git a/pkgs/development/libraries/wxwidgets/3.0/default.nix b/pkgs/development/libraries/wxwidgets/3.0/default.nix
index 6e5b1d83de5..30e807cde05 100644
--- a/pkgs/development/libraries/wxwidgets/3.0/default.nix
+++ b/pkgs/development/libraries/wxwidgets/3.0/default.nix
@@ -4,23 +4,20 @@
 , xorgproto, gst_all_1, setfile
 , libGLSupported ? lib.elem stdenv.hostPlatform.system lib.platforms.mesaPlatforms
 , withMesa ? libGLSupported
-, libGLU ? null, libGL ? null
+, libGLU, libGL
 , compat24 ? false, compat26 ? true, unicode ? true
 , withGtk2 ? true
-, withWebKit ? false, webkitgtk ? null
-, AGL ? null, Carbon ? null, Cocoa ? null, Kernel ? null, QTKit ? null
+, withWebKit ? false, webkitgtk
+, AGL, Carbon, Cocoa, Kernel, QTKit
 }:
 
 with lib;
 
-assert withMesa -> libGLU != null && libGL != null;
-assert withWebKit -> webkitgtk != null;
-
 assert assertMsg (withGtk2 -> withWebKit == false) "wxGTK30: You cannot enable withWebKit when using withGtk2.";
 
 stdenv.mkDerivation rec {
-  version = "3.0.5";
   pname = "wxwidgets";
+  version = "3.0.5";
 
   src = fetchFromGitHub {
     owner = "wxWidgets";
@@ -29,16 +26,16 @@ stdenv.mkDerivation rec {
     sha256 = "1l33629ifx2dl2j71idqbd2qb6zb1d566ijpkvz6irrr50s6gbx7";
   };
 
+  nativeBuildInputs = [ pkg-config ];
+
   buildInputs = [
     libXinerama libSM libXxf86vm xorgproto gst_all_1.gstreamer gst_all_1.gst-plugins-base
-  ] ++ optionals withGtk2 [ gtk2 ]
+  ] ++ optional withGtk2 gtk2
     ++ optional (!withGtk2) gtk3
     ++ optional withMesa libGLU
     ++ optional withWebKit webkitgtk
     ++ optionals stdenv.isDarwin [ setfile Carbon Cocoa Kernel QTKit ];
 
-  nativeBuildInputs = [ pkg-config ];
-
   propagatedBuildInputs = optional stdenv.isDarwin AGL;
 
   patches = [
diff --git a/pkgs/development/python-modules/APScheduler/default.nix b/pkgs/development/python-modules/APScheduler/default.nix
index 32a9dda6c87..507147dc8d6 100644
--- a/pkgs/development/python-modules/APScheduler/default.nix
+++ b/pkgs/development/python-modules/APScheduler/default.nix
@@ -1,8 +1,8 @@
 { lib
 , buildPythonPackage
 , fetchPypi
-, setuptools_scm
-, pytest
+, setuptools-scm
+, pytestCheckHook
 , pytestcov
 , sqlalchemy
 , tornado
@@ -29,11 +29,11 @@ buildPythonPackage rec {
   };
 
   buildInputs = [
-    setuptools_scm
+    setuptools-scm
   ];
 
   checkInputs = [
-    pytest
+    pytestCheckHook
     pytestcov
     sqlalchemy
     tornado
@@ -51,18 +51,11 @@ buildPythonPackage rec {
     setuptools
   ] ++ lib.optional (!isPy3k) futures;
 
-  checkPhase = ''
-    py.test
-  '';
-
   pythonImportsCheck = [ "apscheduler" ];
 
-  # Somehow it cannot find pytestcov
-  doCheck = false;
-
   meta = with lib; {
     description = "A Python library that lets you schedule your Python code to be executed";
-    homepage = "https://pypi.python.org/pypi/APScheduler/";
+    homepage = "https://github.com/agronholm/apscheduler";
     license = licenses.mit;
   };
 }
diff --git a/pkgs/development/python-modules/asdf/default.nix b/pkgs/development/python-modules/asdf/default.nix
index 4006a034d48..19c1921f7c7 100644
--- a/pkgs/development/python-modules/asdf/default.nix
+++ b/pkgs/development/python-modules/asdf/default.nix
@@ -48,5 +48,7 @@ buildPythonPackage rec {
     homepage = "https://github.com/spacetelescope/asdf";
     license = licenses.bsd3;
     maintainers = [ maintainers.costrouc ];
+    # many ValueError in tests
+    broken = true;
   };
 }
diff --git a/pkgs/development/python-modules/cairosvg/default.nix b/pkgs/development/python-modules/cairosvg/default.nix
index 58b8c267306..5e8e8d985aa 100644
--- a/pkgs/development/python-modules/cairosvg/default.nix
+++ b/pkgs/development/python-modules/cairosvg/default.nix
@@ -23,7 +23,7 @@ buildPythonPackage rec {
     sha256 = "sha256-sLmSnPXboAUXjXRqgDb88AJVUPSYylTbYYczIjhHg7w=";
   };
 
-  buildInputs = [ pytest-runner ];
+  nativeBuildInputs = [ pytest-runner ];
 
   propagatedBuildInputs = [ cairocffi cssselect2 defusedxml pillow tinycss2 ];
 
diff --git a/pkgs/development/python-modules/cartopy/default.nix b/pkgs/development/python-modules/cartopy/default.nix
index f41aa6985da..7e3e3206757 100644
--- a/pkgs/development/python-modules/cartopy/default.nix
+++ b/pkgs/development/python-modules/cartopy/default.nix
@@ -54,6 +54,7 @@ buildPythonPackage rec {
     license = licenses.lgpl3;
     homepage = "https://scitools.org.uk/cartopy/docs/latest/";
     maintainers = with maintainers; [ mredaelli ];
+    # following tests fail: test_eccentric_globe and test_ellipse_globe
+    broken = true;
   };
-
 }
diff --git a/pkgs/development/python-modules/clifford/default.nix b/pkgs/development/python-modules/clifford/default.nix
index 3226e3854c7..b26689cf38c 100644
--- a/pkgs/development/python-modules/clifford/default.nix
+++ b/pkgs/development/python-modules/clifford/default.nix
@@ -63,5 +63,7 @@ buildPythonPackage rec {
     homepage = "https://clifford.readthedocs.io";
     license = licenses.bsd3;
     maintainers = [ maintainers.costrouc ];
+    # many TypeError's in tests
+    broken = true;
   };
 }
diff --git a/pkgs/development/python-modules/dask-jobqueue/default.nix b/pkgs/development/python-modules/dask-jobqueue/default.nix
index 8a3174fff3d..7719842fbad 100644
--- a/pkgs/development/python-modules/dask-jobqueue/default.nix
+++ b/pkgs/development/python-modules/dask-jobqueue/default.nix
@@ -29,5 +29,6 @@ buildPythonPackage rec {
     description = "Deploy Dask on job schedulers like PBS, SLURM, and SGE";
     license = licenses.bsd3;
     maintainers = [ maintainers.costrouc ];
+    broken = true;
   };
 }
diff --git a/pkgs/development/python-modules/google-cloud-monitoring/default.nix b/pkgs/development/python-modules/google-cloud-monitoring/default.nix
index fb38954629b..60783d3ded7 100644
--- a/pkgs/development/python-modules/google-cloud-monitoring/default.nix
+++ b/pkgs/development/python-modules/google-cloud-monitoring/default.nix
@@ -35,7 +35,7 @@ buildPythonPackage rec {
 
   meta = with lib; {
     description = "Stackdriver Monitoring API client library";
-    homepage = "https://github.com/GoogleCloudPlatform/google-cloud-python";
+    homepage = "https://github.com/googleapis/python-monitoring";
     license = licenses.asl20;
     maintainers = with maintainers; [ SuperSandro2000 ];
   };
diff --git a/pkgs/development/python-modules/gssapi/default.nix b/pkgs/development/python-modules/gssapi/default.nix
index e5149f6025a..c8149a5fed8 100644
--- a/pkgs/development/python-modules/gssapi/default.nix
+++ b/pkgs/development/python-modules/gssapi/default.nix
@@ -7,7 +7,7 @@
 , decorator
 , nose
 , krb5Full
-, darwin
+, GSS
 , parameterized
 , shouldbe
 , cython
@@ -44,7 +44,7 @@ buildPythonPackage rec {
   ];
 
   buildInputs = lib.optionals stdenv.isDarwin [
-    darwin.apple_sdk.frameworks.GSS
+    GSS
   ];
 
   checkInputs = [
diff --git a/pkgs/development/python-modules/libcst/default.nix b/pkgs/development/python-modules/libcst/default.nix
index 00f8634e47d..fd8c4da6381 100644
--- a/pkgs/development/python-modules/libcst/default.nix
+++ b/pkgs/development/python-modules/libcst/default.nix
@@ -3,7 +3,6 @@
 , fetchFromGitHub
 , pythonOlder
 , hypothesis
-, doCheck ? true
 , dataclasses
 , hypothesmith
 , pytestCheckHook
@@ -29,12 +28,13 @@ buildPythonPackage rec {
 
   disabled = pythonOlder "3.6";
 
-  propagatedBuildInputs = [ hypothesis typing-inspect pyyaml ]
+  propagatedBuildInputs = [ hypothesis typing-extensions typing-inspect pyyaml ]
     ++ lib.optional (pythonOlder "3.7") dataclasses;
 
   checkInputs = [ black hypothesmith isort pytestCheckHook ];
 
-  inherit doCheck;
+  # can't run tests due to circular dependency on hypothesmith -> licst
+  doCheck = false;
 
   preCheck = ''
     python -m libcst.codegen.generate visitors
@@ -44,8 +44,7 @@ buildPythonPackage rec {
   pythonImportsCheck = [ "libcst" ];
 
   meta = with lib; {
-    description =
-      "A Concrete Syntax Tree (CST) parser and serializer library for Python.";
+    description = "A Concrete Syntax Tree (CST) parser and serializer library for Python.";
     homepage = "https://github.com/Instagram/libcst";
     license = with licenses; [ mit asl20 psfl ];
     maintainers = with maintainers; [ ruuda SuperSandro2000 ];
diff --git a/pkgs/development/python-modules/pytorch/default.nix b/pkgs/development/python-modules/pytorch/default.nix
index 98efb169df7..22a87b386e1 100644
--- a/pkgs/development/python-modules/pytorch/default.nix
+++ b/pkgs/development/python-modules/pytorch/default.nix
@@ -1,5 +1,5 @@
 { stdenv, lib, fetchFromGitHub, fetchpatch, buildPythonPackage, python,
-  cudaSupport ? false, cudatoolkit ? null, cudnn ? null, nccl ? null, magma ? null,
+  cudaSupport ? false, cudatoolkit, cudnn, nccl, magma,
   mklDnnSupport ? true, useSystemNccl ? true,
   MPISupport ? false, mpi,
   buildDocs ? false,
@@ -30,8 +30,6 @@
   isPy3k, pythonOlder }:
 
 # assert that everything needed for cuda is present and that the correct cuda versions are used
-assert !cudaSupport || cudatoolkit != null;
-assert cudnn == null || cudatoolkit != null;
 assert !cudaSupport || (let majorIs = lib.versions.major cudatoolkit.version;
                         in majorIs == "9" || majorIs == "10" || majorIs == "11");
 
@@ -297,12 +295,13 @@ in buildPythonPackage rec {
     install_name_tool -change @rpath/libc10.dylib $lib/lib/libc10.dylib $lib/lib/libshm.dylib
   '';
 
-
-  meta = {
+  meta = with lib; {
     description = "Open source, prototype-to-production deep learning platform";
     homepage    = "https://pytorch.org/";
-    license     = lib.licenses.bsd3;
-    platforms   = with lib.platforms; linux ++ lib.optionals (!cudaSupport) darwin;
-    maintainers = with lib.maintainers; [ danieldk teh thoughtpolice tscholak ]; # tscholak esp. for darwin-related builds
+    license     = licenses.bsd3;
+    platforms   = with platforms; linux ++ lib.optionals (!cudaSupport) darwin;
+    maintainers = with maintainers; [ danieldk teh thoughtpolice tscholak ]; # tscholak esp. for darwin-related builds
+    # error: use of undeclared identifier 'noU'; did you mean 'no'?
+    broken = stdenv.isDarwin;
   };
 }
diff --git a/pkgs/development/python-modules/snowflake-connector-python/default.nix b/pkgs/development/python-modules/snowflake-connector-python/default.nix
index 9cbbf8c2dda..0679b25ad41 100644
--- a/pkgs/development/python-modules/snowflake-connector-python/default.nix
+++ b/pkgs/development/python-modules/snowflake-connector-python/default.nix
@@ -33,6 +33,12 @@ buildPythonPackage rec {
     sha256 = "ad62bfd31e677d39984449d9c68e233da2776b80894a988a2421aad412e4c44f";
   };
 
+  postPatch = ''
+    substituteInPlace setup.py \
+      --replace "'pyOpenSSL>=16.2.0,<20.0.0'," "'pyOpenSSL'," \
+      --replace 'pytz<2021.0' 'pytz'
+  '';
+
   propagatedBuildInputs = [
     azure-storage-blob
     asn1crypto
@@ -55,11 +61,6 @@ buildPythonPackage rec {
     urllib3
   ];
 
-  postPatch = ''
-    substituteInPlace setup.py \
-      --replace "'pyOpenSSL>=16.2.0,<20.0.0'," "'pyOpenSSL',"
-  '';
-
   # tests require encrypted secrets, see
   # https://github.com/snowflakedb/snowflake-connector-python/tree/master/.github/workflows/parameters
   doCheck = false;
diff --git a/pkgs/development/python-modules/snowflake-sqlalchemy/default.nix b/pkgs/development/python-modules/snowflake-sqlalchemy/default.nix
index bccca3ee6b6..9ec17443dd8 100644
--- a/pkgs/development/python-modules/snowflake-sqlalchemy/default.nix
+++ b/pkgs/development/python-modules/snowflake-sqlalchemy/default.nix
@@ -27,5 +27,6 @@ buildPythonPackage rec {
     description = "Snowflake SQLAlchemy Dialect";
     homepage = "https://www.snowflake.net/";
     license = licenses.asl20;
+    maintainers = [ ];
   };
 }
diff --git a/pkgs/development/python-modules/watchdog/default.nix b/pkgs/development/python-modules/watchdog/default.nix
index 31f41c50097..ef80dedeb98 100644
--- a/pkgs/development/python-modules/watchdog/default.nix
+++ b/pkgs/development/python-modules/watchdog/default.nix
@@ -1,13 +1,14 @@
-{ lib, stdenv
+{ lib
+, stdenv
 , buildPythonPackage
 , fetchPypi
 , fetchpatch
 , argh
 , pathtools
 , pyyaml
-, pkgs
 , pytest-cov
 , pytestCheckHook
+, CoreServices
 }:
 
 buildPythonPackage rec {
@@ -27,8 +28,7 @@ buildPythonPackage rec {
     })
   ];
 
-  buildInputs = lib.optionals stdenv.isDarwin
-    [ pkgs.darwin.apple_sdk.frameworks.CoreServices ];
+  buildInputs = lib.optionals stdenv.isDarwin [ CoreServices ];
 
   propagatedBuildInputs = [
     argh
@@ -48,6 +48,7 @@ buildPythonPackage rec {
     homepage = "https://github.com/gorakhargosh/watchdog";
     license = licenses.asl20;
     maintainers = with maintainers; [ goibhniu ];
+    # error: use of undeclared identifier 'kFSEventStreamEventFlagItemCloned'
+    broken = stdenv.isDarwin;
   };
-
 }
diff --git a/pkgs/development/tools/build-managers/bear/default.nix b/pkgs/development/tools/build-managers/bear/default.nix
index 5b5a06828a7..e7b0c1d105b 100644
--- a/pkgs/development/tools/build-managers/bear/default.nix
+++ b/pkgs/development/tools/build-managers/bear/default.nix
@@ -60,5 +60,7 @@ stdenv.mkDerivation rec {
     license = licenses.gpl3Plus;
     platforms = platforms.unix;
     maintainers = [ maintainers.babariviere ];
+    # ld: symbol(s) not found for architecture x86_64
+    broken = stdenv.isDarwin;
   };
 }
diff --git a/pkgs/servers/trezord/default.nix b/pkgs/servers/trezord/default.nix
index d0c674c1512..d4f9beecfb7 100644
--- a/pkgs/servers/trezord/default.nix
+++ b/pkgs/servers/trezord/default.nix
@@ -11,16 +11,16 @@ buildGoModule rec {
   version = "2.0.30";
 
   src = fetchFromGitHub {
-    owner  = "trezor";
-    repo   = "trezord-go";
-    rev    = "v${version}";
+    owner = "trezor";
+    repo = "trezord-go";
+    rev = "v${version}";
     sha256 = "1hzvk0wfgg7b4wpqjk3738yqxlv3pj5i7zxwm0jady2h97hmrqrr";
   };
 
   vendorSha256 = "0wb959xzyvr5zzjvkfqc422frmf97q5nr460f02wwx0pj6ch0y61";
 
   propagatedBuildInputs = lib.optionals stdenv.isLinux [ trezor-udev-rules ]
-                       ++ lib.optionals stdenv.isDarwin [ AppKit ];
+    ++ lib.optionals stdenv.isDarwin [ AppKit ];
 
   meta = with lib; {
     description = "Trezor Communication Daemon aka Trezor Bridge";
diff --git a/pkgs/tools/misc/tremor-rs/default.nix b/pkgs/tools/misc/tremor-rs/default.nix
index 0db042120ca..fb1268acc6f 100644
--- a/pkgs/tools/misc/tremor-rs/default.nix
+++ b/pkgs/tools/misc/tremor-rs/default.nix
@@ -33,8 +33,7 @@ rustPlatform.buildRustPackage rec {
   cargoBuildFlags = [ "--all" ];
 
   meta = with lib; {
-    description =
-      "Early stage event processing system for unstructured data with rich support for structural pattern matching, filtering and transformation";
+    description = "Early stage event processing system for unstructured data with rich support for structural pattern matching, filtering and transformation";
     homepage = "https://www.tremor.rs/";
     license = licenses.asl20;
     platforms = [ "x86_64-linux" ];
diff --git a/pkgs/tools/text/shfmt/default.nix b/pkgs/tools/text/shfmt/default.nix
index 85600ff54cf..c6ab5ff9c73 100644
--- a/pkgs/tools/text/shfmt/default.nix
+++ b/pkgs/tools/text/shfmt/default.nix
@@ -32,6 +32,6 @@ buildGoModule rec {
       You can feed it standard input, any number of files or any number of directories to recurse into.
     '';
     license = licenses.bsd3;
-    maintainers = with maintainers; [ zowoq ];
+    maintainers = with maintainers; [ zowoq SuperSandro2000 ];
   };
 }
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 7c9c32111f1..13243ecb181 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -2897,7 +2897,10 @@ in {
 
   gspread = callPackage ../development/python-modules/gspread { };
 
-  gssapi = callPackage ../development/python-modules/gssapi { inherit (pkgs) darwin krb5Full; };
+  gssapi = callPackage ../development/python-modules/gssapi {
+    inherit (pkgs) krb5Full;
+    inherit (pkgs.darwin.apple_sdk.frameworks) GSS;
+  };
 
   gst-python = callPackage ../development/python-modules/gst-python {
     inherit (pkgs) meson;
@@ -3134,9 +3137,7 @@ in {
 
   hypothesis = if isPy3k then callPackage ../development/python-modules/hypothesis { } else self.hypothesis_4;
 
-  hypothesmith = callPackage ../development/python-modules/hypothesmith {
-    libcst = self.libcst.override { doCheck = false; };
-  };
+  hypothesmith = callPackage ../development/python-modules/hypothesmith { };
 
   hyppo = callPackage ../development/python-modules/hyppo { };
 
@@ -8472,7 +8473,9 @@ in {
 
   wasmer = callPackage ../development/python-modules/wasmer { };
 
-  watchdog = callPackage ../development/python-modules/watchdog { };
+  watchdog = callPackage ../development/python-modules/watchdog {
+    inherit (pkgs.darwin.apple_sdk.frameworks) CoreServices;
+  };
 
   waterfurnace = callPackage ../development/python-modules/waterfurnace { };