diff --git a/pkgs/applications/networking/lieer/default.nix b/pkgs/applications/networking/lieer/default.nix
index 83d009e40e83..aee21dca6458 100644
--- a/pkgs/applications/networking/lieer/default.nix
+++ b/pkgs/applications/networking/lieer/default.nix
@@ -19,18 +19,22 @@ python3Packages.buildPythonApplication rec {
     setuptools
   ];
 
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "lieer" ];
+
   meta = with lib; {
-    description      = "Fast email-fetching and two-way tag synchronization between notmuch and GMail";
-    longDescription  = ''
+    description = "Fast email-fetching and two-way tag synchronization between notmuch and GMail";
+    longDescription = ''
       This program can pull email and labels (and changes to labels)
       from your GMail account and store them locally in a maildir with
       the labels synchronized with a notmuch database. The changes to
       tags in the notmuch database may be pushed back remotely to your
       GMail account.
     '';
-    homepage         = "https://lieer.gaute.vetsj.com/";
+    homepage = "https://lieer.gaute.vetsj.com/";
     repositories.git = "https://github.com/gauteh/lieer.git";
-    license          = licenses.gpl3Plus;
-    maintainers      = with maintainers; [ flokli kaiha ];
+    license = licenses.gpl3Plus;
+    maintainers = with maintainers; [ flokli kaiha ];
   };
 }
diff --git a/pkgs/applications/science/math/nasc/default.nix b/pkgs/applications/science/math/nasc/default.nix
index 40406cc45889..37173f819785 100644
--- a/pkgs/applications/science/math/nasc/default.nix
+++ b/pkgs/applications/science/math/nasc/default.nix
@@ -1,6 +1,7 @@
 { lib, stdenv
 , fetchFromGitHub
 , pkgconfig
+, fetchpatch
 , python3
 , meson
 , ninja
@@ -31,6 +32,16 @@ stdenv.mkDerivation rec {
     fetchSubmodules = true;
   };
 
+  patches = [
+    # fix compilation with gcc10
+    (fetchpatch {
+      url = "https://github.com/parnold-x/libqalculate/commit/4fa8f2cceada128ef19f82407226b2c230b780d5.patch";
+      extraPrefix = "subprojects/libqalculate/";
+      stripLen = "1";
+      sha256 = "0kbff623zl0s6yx5avx068f2apwzxzvihjahja4qhlkqkhhzj9dm";
+    })
+  ];
+
   nativeBuildInputs = [
     glib # post_install.py
     gtk3 # post_install.py
diff --git a/pkgs/applications/video/gnomecast/default.nix b/pkgs/applications/video/gnomecast/default.nix
index 486159135055..bc045deb9ecb 100644
--- a/pkgs/applications/video/gnomecast/default.nix
+++ b/pkgs/applications/video/gnomecast/default.nix
@@ -20,6 +20,9 @@ buildPythonApplication rec {
     gappsWrapperArgs+=(--prefix PATH : ${lib.makeBinPath [ ffmpeg_3 ]})
   '';
 
+  # no tests
+  doCheck = false;
+
   meta = with lib; {
     description = "A native Linux GUI for Chromecasting local files";
     homepage = "https://github.com/keredson/gnomecast";
diff --git a/pkgs/development/python-modules/cliff/default.nix b/pkgs/development/python-modules/cliff/default.nix
index f25170cc6ae7..1c551bfb0d90 100644
--- a/pkgs/development/python-modules/cliff/default.nix
+++ b/pkgs/development/python-modules/cliff/default.nix
@@ -7,12 +7,11 @@
 , six
 , stevedore
 , pyyaml
-, unicodecsv
 , cmd2
-, pytest
-, mock
+, pytestCheckHook
 , testtools
 , fixtures
+, which
 }:
 
 buildPythonPackage rec {
@@ -32,20 +31,21 @@ buildPythonPackage rec {
     stevedore
     pyyaml
     cmd2
-    unicodecsv
   ];
 
-  # remove version constraints
   postPatch = ''
-    sed -i '/cmd2/c\cmd2' requirements.txt
+    sed -i -e '/cmd2/c\cmd2' -e '/PrettyTable/c\PrettyTable' requirements.txt
   '';
 
-  checkInputs = [ fixtures mock pytest testtools ];
+  checkInputs = [ fixtures pytestCheckHook testtools which ];
   # add some tests
-  checkPhase = ''
-    pytest cliff/tests/test_{utils,app,command,help,lister}.py \
-      -k 'not interactive_mode'
-  '';
+  pytestFlagsArray = [
+    "cliff/tests/test_utils.py"
+    "cliff/tests/test_app.py"
+    "cliff/tests/test_command.py"
+    "cliff/tests/test_help.py"
+    "cliff/tests/test_lister.py"
+  ];
 
   meta = with lib; {
     description = "Command Line Interface Formulation Framework";
diff --git a/pkgs/development/python-modules/geopandas/default.nix b/pkgs/development/python-modules/geopandas/default.nix
index bee22eb98bda..70963a85d41d 100644
--- a/pkgs/development/python-modules/geopandas/default.nix
+++ b/pkgs/development/python-modules/geopandas/default.nix
@@ -29,10 +29,6 @@ buildPythonPackage rec {
     })
   ];
 
-  checkInputs = [ pytestCheckHook Rtree ];
-  disabledTests = [ "web" ];
-  pytestFlagsArray = [ "geopandas" ];
-
   propagatedBuildInputs = [
     pandas
     shapely
@@ -41,6 +37,11 @@ buildPythonPackage rec {
     pyproj
   ];
 
+  doCheck = !stdenv.isDarwin;
+  checkInputs = [ pytestCheckHook Rtree ];
+  disabledTests = [ "web" ];
+  pytestFlagsArray = [ "geopandas" ];
+
   meta = with lib; {
     description = "Python geospatial data analysis framework";
     homepage = "https://geopandas.org";
diff --git a/pkgs/development/python-modules/guestfs/default.nix b/pkgs/development/python-modules/guestfs/default.nix
index fd12aab81b4a..23a2545525a3 100644
--- a/pkgs/development/python-modules/guestfs/default.nix
+++ b/pkgs/development/python-modules/guestfs/default.nix
@@ -11,6 +11,10 @@ buildPythonPackage rec {
 
   propagatedBuildInputs = [ libguestfs qemu ];
 
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "guestfs" ];
+
   meta = with lib; {
     homepage = "https://libguestfs.org/guestfs-python.3.html";
     description = "Use libguestfs from Python";
diff --git a/pkgs/development/python-modules/keep/default.nix b/pkgs/development/python-modules/keep/default.nix
index 52fc90a3ca90..22ae853c043c 100644
--- a/pkgs/development/python-modules/keep/default.nix
+++ b/pkgs/development/python-modules/keep/default.nix
@@ -24,6 +24,7 @@ buildPythonPackage rec {
   ];
 
   # no tests
+  doCheck = false;
   pythonImportsCheck = [ "keep" ];
 
   meta = with lib; {
diff --git a/pkgs/development/python-modules/notmuch/2.nix b/pkgs/development/python-modules/notmuch/2.nix
index 171b88108708..970928e03f40 100644
--- a/pkgs/development/python-modules/notmuch/2.nix
+++ b/pkgs/development/python-modules/notmuch/2.nix
@@ -1,4 +1,5 @@
-{ lib, stdenv
+{ lib
+, stdenv
 , buildPythonPackage
 , notmuch
 , python
@@ -13,6 +14,10 @@ buildPythonPackage {
 
   buildInputs = [ python notmuch cffi ];
 
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "notmuch2" ];
+
   meta = with lib; {
     description = "Pythonic bindings for the notmuch mail database using CFFI";
     homepage = "https://notmuchmail.org/";
diff --git a/pkgs/development/python-modules/notmuch/default.nix b/pkgs/development/python-modules/notmuch/default.nix
index 173f332b3146..609d4c78d5d7 100644
--- a/pkgs/development/python-modules/notmuch/default.nix
+++ b/pkgs/development/python-modules/notmuch/default.nix
@@ -1,4 +1,5 @@
-{ lib, stdenv
+{ lib
+, stdenv
 , buildPythonPackage
 , notmuch
 , python
@@ -16,6 +17,10 @@ buildPythonPackage {
       notmuch/globals.py
   '';
 
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "notmuch" ];
+
   meta = with lib; {
     description = "A Python wrapper around notmuch";
     homepage = "https://notmuchmail.org/";
diff --git a/pkgs/development/python-modules/pyhaversion/default.nix b/pkgs/development/python-modules/pyhaversion/default.nix
index 1a32851e6f38..27d750a5df76 100644
--- a/pkgs/development/python-modules/pyhaversion/default.nix
+++ b/pkgs/development/python-modules/pyhaversion/default.nix
@@ -1,24 +1,16 @@
 { lib
 , buildPythonPackage
 , fetchPypi
-, isPy3k
-# propagatedBuildInputs
+, pythonOlder
 , aiohttp
 , async-timeout
 , semantic-version
-# buildInputs
 , pytestrunner
-# checkInputs
-, pytest
-, pytest-asyncio
-, aresponses
 }:
 buildPythonPackage rec {
   pname = "pyhaversion";
   version = "3.4.2";
-
-  # needs aiohttp which is py3k-only
-  disabled = !isPy3k;
+  disabled = pythonOlder "3.8";
 
   src = fetchPypi {
     inherit pname version;
@@ -35,15 +27,14 @@ buildPythonPackage rec {
     pytestrunner
   ];
 
-  checkInputs = [
-    pytest
-    pytest-asyncio
-    aresponses
-  ];
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "pyhaversion" ];
 
   meta = with lib; {
     description = "A python module to the newest version number of Home Assistant";
     homepage = "https://github.com/ludeeus/pyhaversion";
+    license = with licenses; [ mit ];
     maintainers = [ maintainers.makefu ];
   };
 }
diff --git a/pkgs/development/python-modules/pyls-spyder/default.nix b/pkgs/development/python-modules/pyls-spyder/default.nix
new file mode 100644
index 000000000000..7e1fa0606191
--- /dev/null
+++ b/pkgs/development/python-modules/pyls-spyder/default.nix
@@ -0,0 +1,24 @@
+{ lib, buildPythonPackage, fetchPypi, python-language-server }:
+
+buildPythonPackage rec {
+  pname = "pyls-spyder";
+  version = "0.3.0";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "07apxh12b8ybkx5izr7pg8kbg5g5wgzw7vh5iy2n8dhiqarzp7s1";
+  };
+
+  propagatedBuildInputs = [ python-language-server ];
+
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "pyls_spyder" ];
+
+  meta = with lib; {
+    description = "Spyder extensions for the python-language-server";
+    homepage = "https://github.com/spyder-ide/pyls-spyder";
+    license = licenses.mit;
+    maintainers = with maintainers; [ SuperSandro2000 ];
+  };
+}
diff --git a/pkgs/development/python-modules/python-jsonrpc-server/default.nix b/pkgs/development/python-modules/python-jsonrpc-server/default.nix
index 1f33bac68273..9879a441b3e2 100644
--- a/pkgs/development/python-modules/python-jsonrpc-server/default.nix
+++ b/pkgs/development/python-modules/python-jsonrpc-server/default.nix
@@ -1,43 +1,25 @@
-{ lib, stdenv, buildPythonPackage, fetchFromGitHub, pythonOlder
-, pytest, mock, pytestcov, coverage
+{ stdenv, lib, buildPythonPackage, fetchFromGitHub, pythonOlder
+, pytestCheckHook, mock, pytestcov, coverage
 , future, futures, ujson, isPy38
-, fetchpatch
 }:
 
 buildPythonPackage rec {
   pname = "python-jsonrpc-server";
-  version = "0.3.4";
+  version = "0.4.0";
 
   src = fetchFromGitHub {
     owner = "palantir";
     repo = "python-jsonrpc-server";
     rev = version;
-    sha256 = "027sx5pv4i9a192kr00bjjcxxprh2xyr8q5372q8ghff3xryk9dd";
+    sha256 = "0pcf50qvcxqnz3db58whqd8z89cdph19pfs1whgfm0zmwbwk0lw6";
   };
 
   postPatch = ''
     sed -i "s/version=versioneer.get_version(),/version=\"$version\",/g" setup.py
-    # https://github.com/palantir/python-jsonrpc-server/issues/36
-    sed -iEe "s!'ujson.*\$!'ujson',!" setup.py
   '';
 
   checkInputs = [
-    pytest mock pytestcov coverage
-  ];
-
-  checkPhase = ''
-    pytest
-  '';
-
-  patches = [
-    (fetchpatch {
-      url = "https://github.com/palantir/python-jsonrpc-server/commit/0a04cc4e9d44233b1038b12d63cd3bd437c2374e.patch";
-      sha256 = "177zdnp1808r2pg189bvzab44l8i2alsgv04kmrlhhnv40h66qyg";
-    })
-    (fetchpatch {
-      url = "https://github.com/palantir/python-jsonrpc-server/commit/5af6e43d0c1fb9a6a29b96d38cfd6dbeec85d0ea.patch";
-      sha256 = "1gx7lc1jxar1ngqqfkdn21s46y1mfnjf7ky2886ydk53nkaba91m";
-    })
+    pytestCheckHook mock pytestcov coverage
   ];
 
   propagatedBuildInputs = [ future ujson ]
diff --git a/pkgs/development/python-modules/python-language-server/default.nix b/pkgs/development/python-modules/python-language-server/default.nix
index 757194d11a50..dc3b33a6f539 100644
--- a/pkgs/development/python-modules/python-language-server/default.nix
+++ b/pkgs/development/python-modules/python-language-server/default.nix
@@ -1,6 +1,6 @@
-{ lib, stdenv, buildPythonPackage, fetchFromGitHub, fetchpatch, pythonOlder, isPy27
+{ stdenv, lib, buildPythonPackage, fetchFromGitHub, pythonOlder, isPy27
 , backports_functools_lru_cache, configparser, futures, future, jedi, pluggy, python-jsonrpc-server, flake8
-, pytestCheckHook, mock, pytestcov, coverage, setuptools, ujson
+, pytestCheckHook, mock, pytestcov, coverage, setuptools, ujson, flaky
 , # Allow building a limited set of providers, e.g. ["pycodestyle"].
   providers ? ["*"]
   # The following packages are optional and
@@ -21,33 +21,33 @@ in
 
 buildPythonPackage rec {
   pname = "python-language-server";
-  version = "0.34.1";
+  version = "0.36.2";
 
   src = fetchFromGitHub {
     owner = "palantir";
     repo = "python-language-server";
     rev = version;
-    sha256 = "sha256-/tVzaoyUO6+7DSvnf3JxpcTY0rU+hHBu5qlru/ZTpxU=";
+    sha256 = "07x6jr4z20jxn03bxblwc8vk0ywha492cgwfhj7q97nb5cm7kx0q";
   };
 
-  patches = [
-    # https://github.com/palantir/python-language-server/pull/851
-    (fetchpatch {
-      url = "https://github.com/palantir/python-language-server/commit/f513f3297132492dd41e001d943980e6c4f40809.patch";
-      sha256 = "04c9hrb3dzlfchjk4625ipazyfcbq6qq2kj2hg3zf2xsny2jcvi5";
-    })
-  ];
+  propagatedBuildInputs = [ setuptools jedi pluggy future python-jsonrpc-server flake8 ujson ]
+    ++ stdenv.lib.optional (withProvider "autopep8") autopep8
+    ++ stdenv.lib.optional (withProvider "mccabe") mccabe
+    ++ stdenv.lib.optional (withProvider "pycodestyle") pycodestyle
+    ++ stdenv.lib.optional (withProvider "pydocstyle") pydocstyle
+    ++ stdenv.lib.optional (withProvider "pyflakes") pyflakes
+    ++ stdenv.lib.optional (withProvider "pylint") pylint
+    ++ stdenv.lib.optional (withProvider "rope") rope
+    ++ stdenv.lib.optional (withProvider "yapf") yapf
+    ++ stdenv.lib.optional isPy27 configparser
+    ++ stdenv.lib.optionals (pythonOlder "3.2") [ backports_functools_lru_cache futures ];
 
-  postPatch = ''
-    # https://github.com/palantir/python-jsonrpc-server/issues/36
-    sed -i -e 's!ujson<=!ujson>=!' setup.py
-  '';
 
   # The tests require all the providers, disable otherwise.
   doCheck = providers == ["*"];
 
   checkInputs = [
-    pytestCheckHook mock pytestcov coverage
+    pytestCheckHook mock pytestcov coverage flaky
     # rope is technically a dependency, but we don't add it by default since we
     # already have jedi, which is the preferred option
     rope
@@ -67,20 +67,9 @@ buildPythonPackage rec {
     "test_matplotlib_completions"
     "test_snippet_parsing"
     "test_numpy_hover"
+    "test_symbols"
   ] ++ stdenv.lib.optional isPy27 "test_flake8_lint";
 
-  propagatedBuildInputs = [ setuptools jedi pluggy future python-jsonrpc-server flake8 ujson ]
-    ++ stdenv.lib.optional (withProvider "autopep8") autopep8
-    ++ stdenv.lib.optional (withProvider "mccabe") mccabe
-    ++ stdenv.lib.optional (withProvider "pycodestyle") pycodestyle
-    ++ stdenv.lib.optional (withProvider "pydocstyle") pydocstyle
-    ++ stdenv.lib.optional (withProvider "pyflakes") pyflakes
-    ++ stdenv.lib.optional (withProvider "pylint") pylint
-    ++ stdenv.lib.optional (withProvider "rope") rope
-    ++ stdenv.lib.optional (withProvider "yapf") yapf
-    ++ stdenv.lib.optional isPy27 configparser
-    ++ stdenv.lib.optionals (pythonOlder "3.2") [ backports_functools_lru_cache futures ];
-
   meta = with lib; {
     homepage = "https://github.com/palantir/python-language-server";
     description = "An implementation of the Language Server Protocol for Python";
diff --git a/pkgs/development/python-modules/pytile/default.nix b/pkgs/development/python-modules/pytile/default.nix
index d2fd99f6d166..52b3d828dedf 100644
--- a/pkgs/development/python-modules/pytile/default.nix
+++ b/pkgs/development/python-modules/pytile/default.nix
@@ -43,6 +43,8 @@ buildPythonPackage rec {
   pytestFlagsArray = [ "--ignore examples/" ];
   pythonImportsCheck = [ "pytile" ];
 
+  __darwinAllowLocalNetworking = true;
+
   meta = with lib; {
     description = " Python API for Tile Bluetooth trackers";
     longDescription = ''
diff --git a/pkgs/development/python-modules/scrapy-deltafetch/default.nix b/pkgs/development/python-modules/scrapy-deltafetch/default.nix
index 090d31e67a9a..900943a0e153 100644
--- a/pkgs/development/python-modules/scrapy-deltafetch/default.nix
+++ b/pkgs/development/python-modules/scrapy-deltafetch/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchPypi, buildPythonPackage, pytest, scrapy, bsddb3 }:
+{ stdenv, lib, fetchPypi, buildPythonPackage, scrapy, bsddb3 }:
 
 buildPythonPackage rec {
   pname = "scrapy-deltafetch";
@@ -11,7 +11,9 @@ buildPythonPackage rec {
 
   propagatedBuildInputs = [ bsddb3 scrapy ];
 
-  checkInputs = [ pytest ];
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "scrapy_deltafetch" ];
 
   meta = with lib; {
     description = "Scrapy spider middleware to ignore requests to pages containing items seen in previous crawls";
diff --git a/pkgs/development/python-modules/scrapy-splash/default.nix b/pkgs/development/python-modules/scrapy-splash/default.nix
index 48988be2c0a7..ab00377f4a0e 100644
--- a/pkgs/development/python-modules/scrapy-splash/default.nix
+++ b/pkgs/development/python-modules/scrapy-splash/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchPypi, buildPythonPackage, pytest, hypothesis, scrapy }:
+{ stdenv, lib, fetchPypi, buildPythonPackage, scrapy, six }:
 
 buildPythonPackage rec {
   pname = "scrapy-splash";
@@ -9,7 +9,11 @@ buildPythonPackage rec {
     sha256 = "1dg7csdza2hzqskd9b9gx0v3saqsch4f0fwdp0a3p0822aqqi488";
   };
 
-  checkInputs = [ pytest hypothesis scrapy ];
+  propagatedBuildInputs = [ scrapy six ];
+
+  # no tests
+  doCheck = false;
+  pythonImportsCheck = [ "scrapy_splash" ];
 
   meta = with lib; {
     description = "Scrapy+Splash for JavaScript integration";
diff --git a/pkgs/development/python-modules/scrapy/default.nix b/pkgs/development/python-modules/scrapy/default.nix
index 1b7b75eaff4f..48bafa41dff7 100644
--- a/pkgs/development/python-modules/scrapy/default.nix
+++ b/pkgs/development/python-modules/scrapy/default.nix
@@ -1,4 +1,5 @@
-{ lib, stdenv
+{ lib
+, stdenv
 , buildPythonPackage
 , isPy27
 , fetchPypi
@@ -79,7 +80,10 @@ buildPythonPackage rec {
     "test_retry_dns_error"
     "test_custom_asyncio_loop_enabled_true"
     "test_custom_loop_asyncio"
-  ] ++ stdenv.lib.optionals stdenv.isDarwin [ "test_xmliter_encoding" ];
+  ] ++ stdenv.lib.optionals stdenv.isDarwin [
+    "test_xmliter_encoding"
+    "test_download"
+  ];
 
   src = fetchPypi {
     inherit pname version;
@@ -92,6 +96,8 @@ buildPythonPackage rec {
     install -m 644 -D extras/scrapy_zsh_completion $out/share/zsh/site-functions/_scrapy
   '';
 
+  __darwinAllowLocalNetworking = true;
+
   meta = with lib; {
     description = "A fast high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages";
     homepage = "https://scrapy.org/";
diff --git a/pkgs/development/python-modules/spyder/default.nix b/pkgs/development/python-modules/spyder/default.nix
index a47a1278425d..de1b8123dd97 100644
--- a/pkgs/development/python-modules/spyder/default.nix
+++ b/pkgs/development/python-modules/spyder/default.nix
@@ -2,7 +2,7 @@
   psutil, pyflakes, rope, numpy, scipy, matplotlib, pylint, keyring, numpydoc,
   qtconsole, qtawesome, nbconvert, mccabe, pyopengl, cloudpickle, pygments,
   spyder-kernels, qtpy, pyzmq, chardet, qdarkstyle, watchdog, python-language-server
-, pyqtwebengine, atomicwrites, pyxdg, diff-match-patch
+, pyqtwebengine, atomicwrites, pyxdg, diff-match-patch, three-merge, pyls-black, pyls-spyder
 }:
 
 buildPythonPackage rec {
@@ -22,7 +22,7 @@ buildPythonPackage rec {
     intervaltree jedi pycodestyle psutil pyflakes rope numpy scipy matplotlib pylint keyring
     numpydoc qtconsole qtawesome nbconvert mccabe pyopengl cloudpickle spyder-kernels
     pygments qtpy pyzmq chardet pyqtwebengine qdarkstyle watchdog python-language-server
-    atomicwrites pyxdg diff-match-patch
+    atomicwrites pyxdg diff-match-patch three-merge pyls-black pyls-spyder
   ];
 
   # There is no test for spyder
@@ -51,7 +51,7 @@ buildPythonPackage rec {
   postInstall = ''
     # add Python libs to env so Spyder subprocesses
     # created to run compute kernels don't fail with ImportErrors
-    wrapProgram $out/bin/spyder3 --prefix PYTHONPATH : "$PYTHONPATH"
+    wrapProgram $out/bin/spyder --prefix PYTHONPATH : "$PYTHONPATH"
 
     # Create desktop item
     mkdir -p $out/share/icons
diff --git a/pkgs/development/python-modules/swspotify/default.nix b/pkgs/development/python-modules/swspotify/default.nix
index 30f34c56c81a..321a48e72b6f 100644
--- a/pkgs/development/python-modules/swspotify/default.nix
+++ b/pkgs/development/python-modules/swspotify/default.nix
@@ -18,7 +18,8 @@ buildPythonPackage rec {
 
   preConfigure = ''
     substituteInPlace setup.py \
-      --replace 'requests>=2.24.0' 'requests~=2.23'
+      --replace 'requests>=2.24.0' 'requests~=2.23' \
+      --replace 'flask-cors==3.0.8' 'flask-cors'
   '';
 
   checkPhase = ''
@@ -27,6 +28,8 @@ buildPythonPackage rec {
 
   checkInputs = [ pytestCheckHook mock ];
 
+  pythonImportsCheck = [ "SwSpotify" ];
+
   meta = with lib; {
     homepage = "https://github.com/SwagLyrics/SwSpotify";
     description = "Library to get the currently playing song and artist from Spotify";
diff --git a/pkgs/development/python-modules/three-merge/default.nix b/pkgs/development/python-modules/three-merge/default.nix
new file mode 100644
index 000000000000..dab312c88455
--- /dev/null
+++ b/pkgs/development/python-modules/three-merge/default.nix
@@ -0,0 +1,24 @@
+{ lib, buildPythonPackage, fetchPypi, diff-match-patch }:
+
+buildPythonPackage rec {
+  pname = "three-merge";
+  version = "0.1.1";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0w6rv7rv1zm901wbjkmm6d3vkwyf3csja9p37bb60mar8khszxk0";
+  };
+
+  propagatedBuildInputs = [ diff-match-patch ];
+
+  dontUseSetuptoolsCheck = true;
+
+  pythonImportsCheck = [ "three_merge" ];
+
+  meta = with lib; {
+    description = "Simple library for merging two strings with respect to a base one";
+    homepage = "https://github.com/spyder-ide/three-merge";
+    license = licenses.mit;
+    maintainers = with maintainers; [ SuperSandro2000 ];
+  };
+}
diff --git a/pkgs/development/python-modules/worldengine/default.nix b/pkgs/development/python-modules/worldengine/default.nix
index fb7326c81d5b..51c0de77917d 100644
--- a/pkgs/development/python-modules/worldengine/default.nix
+++ b/pkgs/development/python-modules/worldengine/default.nix
@@ -3,7 +3,6 @@
 , pythonOlder
 , isPy27
 , fetchFromGitHub
-, nose
 , noise
 , numpy
 , pyplatec
@@ -11,6 +10,7 @@
 , purepng
 , h5py
 , gdal
+, pytestCheckHook
 }:
 
 buildPythonPackage rec {
@@ -47,13 +47,12 @@ buildPythonPackage rec {
       --replace 'PyPlatec==1.4.0' 'PyPlatec' \
   '';
 
-  # with python<3.5, unittest fails to discover tests because of their filenames
-  # so nose is used instead.
   doCheck = !isPy27; # google namespace clash
-  checkInputs = stdenv.lib.optional (pythonOlder "3.5") [ nose ];
-  postCheck = stdenv.lib.optionalString (pythonOlder "3.5") ''
-    nosetests tests
-  '';
+  checkInputs = [ pytestCheckHook ];
+
+  disabledTests = [
+    "TestSerialization"
+  ];
 
   meta = with lib; {
     homepage = "http://world-engine.org";
diff --git a/pkgs/development/python-modules/xdot/default.nix b/pkgs/development/python-modules/xdot/default.nix
index 75d090699a47..21b45b9c322d 100644
--- a/pkgs/development/python-modules/xdot/default.nix
+++ b/pkgs/development/python-modules/xdot/default.nix
@@ -20,7 +20,8 @@ buildPythonPackage rec {
   '';
 
   # https://github.com/NixOS/nixpkgs/pull/107872#issuecomment-752175866
-  doCheck = stdenv.isLinux;
+  # cannot import name '_gi' from partially initialized module 'gi' (most likely due to a circular import)
+  doCheck = false;
 
   meta = with lib; {
     description = "An interactive viewer for graphs written in Graphviz's dot";
diff --git a/pkgs/tools/misc/nagstamon/default.nix b/pkgs/tools/misc/nagstamon/default.nix
index 7f3c3ed4d560..3bd297628b2d 100644
--- a/pkgs/tools/misc/nagstamon/default.nix
+++ b/pkgs/tools/misc/nagstamon/default.nix
@@ -20,6 +20,8 @@ pythonPackages.buildPythonApplication rec {
     homepage = "https://nagstamon.ifw-dresden.de/";
     license = licenses.gpl2;
     maintainers = with maintainers; [ pSub ];
-    inherit version;
+    # fails to install with:
+    # TypeError: cannot unpack non-iterable bool object
+    broken = true;
   };
 }
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index f0c59ea91e27..97cea2be45fe 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -5450,6 +5450,8 @@ in {
 
   pyls-mypy = callPackage ../development/python-modules/pyls-mypy { };
 
+  pyls-spyder = callPackage ../development/python-modules/pyls-spyder { };
+
   PyLTI = callPackage ../development/python-modules/pylti { };
 
   pymacaroons = callPackage ../development/python-modules/pymacaroons { };
@@ -7508,6 +7510,8 @@ in {
 
   threadpoolctl = callPackage ../development/python-modules/threadpoolctl { };
 
+  three-merge = callPackage ../development/python-modules/three-merge { };
+
   thrift = callPackage ../development/python-modules/thrift { };
 
   thumbor = callPackage ../development/python-modules/thumbor { };