diff --git a/pkgs/development/python-modules/hypothesmith/default.nix b/pkgs/development/python-modules/hypothesmith/default.nix
index a69c0c08214e4..c53c3c2e3670c 100644
--- a/pkgs/development/python-modules/hypothesmith/default.nix
+++ b/pkgs/development/python-modules/hypothesmith/default.nix
@@ -1,5 +1,6 @@
 {
   lib,
+  black,
   buildPythonPackage,
   fetchPypi,
   hypothesis,
@@ -7,59 +8,45 @@
   libcst,
   parso,
   pytestCheckHook,
+  pytest-cov-stub,
   pytest-xdist,
   pythonOlder,
+  setuptools,
 }:
 
 buildPythonPackage rec {
   pname = "hypothesmith";
   version = "0.3.3";
-  format = "setuptools";
+  pyproject = true;
 
-  disabled = pythonOlder "3.8";
+  disabled = pythonOlder "3.9";
 
   src = fetchPypi {
     inherit pname version;
     hash = "sha256-lsFIAtbI6F2JdSZBdoeNtUso0u2SH9v+3C5rjOPIFxY=";
   };
 
-  patches = [ ./remove-black.patch ];
+  build-system = [ setuptools ];
 
-  postPatch = ''
-    substituteInPlace setup.py \
-      --replace "lark-parser" "lark"
-
-    substituteInPlace tox.ini \
-      --replace "--cov=hypothesmith" "" \
-      --replace "--cov-branch" "" \
-      --replace "--cov-report=term-missing:skip-covered" "" \
-      --replace "--cov-fail-under=100" ""
-  '';
-
-  propagatedBuildInputs = [
+  dependencies = [
     hypothesis
     lark
     libcst
   ];
 
   nativeCheckInputs = [
+    black
     parso
     pytestCheckHook
+    pytest-cov-stub
     pytest-xdist
   ];
 
-  pytestFlagsArray = [ "-v" ];
-
   disabledTests = [
-    # https://github.com/Zac-HD/hypothesmith/issues/21
+    # super slow
     "test_source_code_from_libcst_node_type"
   ];
 
-  disabledTestPaths = [
-    # missing blib2to3
-    "tests/test_syntactic.py"
-  ];
-
   pythonImportsCheck = [ "hypothesmith" ];
 
   meta = with lib; {
diff --git a/pkgs/development/python-modules/hypothesmith/remove-black.patch b/pkgs/development/python-modules/hypothesmith/remove-black.patch
deleted file mode 100644
index d37222ef4b2ce..0000000000000
--- a/pkgs/development/python-modules/hypothesmith/remove-black.patch
+++ /dev/null
@@ -1,87 +0,0 @@
-diff --git a/tests/test_cst.py b/tests/test_cst.py
-index 8532240..bdba2d7 100644
---- a/tests/test_cst.py
-+++ b/tests/test_cst.py
-@@ -3,7 +3,6 @@ import ast
- from inspect import isabstract
- from operator import attrgetter
- 
--import black
- import libcst
- import parso
- import pytest
-@@ -51,27 +50,6 @@ def test_ast_unparse_from_nodes(source_code):
-     assert ast.dump(first) == ast.dump(second)
- 
- 
--@pytest.mark.xfail
--@example("A\u2592", black.Mode())
--@given(
--    source_code=hypothesmith.from_node(),
--    mode=st.builds(
--        black.Mode,
--        line_length=st.just(88) | st.integers(0, 200),
--        string_normalization=st.booleans(),
--        is_pyi=st.booleans(),
--    ),
--)
--def test_black_autoformatter_from_nodes(source_code, mode):
--    try:
--        result = black.format_file_contents(source_code, fast=False, mode=mode)
--    except black.NothingChanged:
--        pass
--    else:
--        with pytest.raises(black.NothingChanged):
--            black.format_file_contents(result, fast=False, mode=mode)
--
--
- @given(source_code=hypothesmith.from_node())
- def test_from_node_always_compilable(source_code):
-     compile(source_code, "<string>", "exec")
-diff --git a/tests/test_syntactic.py b/tests/test_syntactic.py
-index 7fe9835..17c4f7c 100644
---- a/tests/test_syntactic.py
-+++ b/tests/test_syntactic.py
-@@ -3,7 +3,6 @@ import ast
- import io
- import tokenize
- 
--import black
- import blib2to3
- import parso
- import pytest
-@@ -58,34 +57,6 @@ def test_ast_unparse_from_grammar(source_code):
-     assert ast.dump(first) == ast.dump(second)
- 
- 
--@example("\\", black.Mode())
--@example("A#\r#", black.Mode())
--@given(
--    source_code=hypothesmith.from_grammar(),
--    mode=st.builds(
--        black.Mode,
--        line_length=st.just(88) | st.integers(0, 200),
--        string_normalization=st.booleans(),
--        is_pyi=st.booleans(),
--    ),
--)
--def test_black_autoformatter_from_grammar(source_code, mode):
--    try:
--        result = black.format_file_contents(source_code, fast=False, mode=mode)
--    except black.NothingChanged:
--        pass
--    except blib2to3.pgen2.tokenize.TokenError:
--        # Fails to tokenise e.g. "\\", though compile("\\", "<string>", "exec") works.
--        # See https://github.com/psf/black/issues/1012
--        reject()
--    except black.InvalidInput:
--        # e.g. "A#\r#", see https://github.com/psf/black/issues/970
--        reject()
--    else:
--        with pytest.raises(black.NothingChanged):
--            black.format_file_contents(result, fast=False, mode=mode)
--
--
- @given(source_code=hypothesmith.from_grammar("eval_input"))
- def test_eval_input_generation(source_code):
-     compile(source_code, filename="<string>", mode="eval")
diff --git a/pkgs/development/python-modules/libcst/default.nix b/pkgs/development/python-modules/libcst/default.nix
index ab176fd8252f1..a0863f9bfd1cb 100644
--- a/pkgs/development/python-modules/libcst/default.nix
+++ b/pkgs/development/python-modules/libcst/default.nix
@@ -3,8 +3,10 @@
   stdenv,
   buildPythonPackage,
   fetchFromGitHub,
+  callPackage,
   cargo,
-  hypothesis,
+  hypothesmith,
+  libcst,
   libiconv,
   pytestCheckHook,
   python,
@@ -16,14 +18,15 @@
   setuptools-scm,
   typing-extensions,
   typing-inspect,
+  ufmt,
 }:
 
 buildPythonPackage rec {
   pname = "libcst";
   version = "1.4.0";
-  format = "pyproject";
+  pyproject = true;
 
-  disabled = pythonOlder "3.7";
+  disabled = pythonOlder "3.9";
 
   src = fetchFromGitHub {
     owner = "instagram";
@@ -41,15 +44,12 @@ buildPythonPackage rec {
 
   cargoRoot = "native";
 
-  postPatch = ''
-    # avoid infinite recursion by not formatting the release files
-    substituteInPlace libcst/codegen/generate.py \
-      --replace '"ufmt"' '"true"'
-  '';
-
-  nativeBuildInputs = [
+  build-system = [
     setuptools-rust
     setuptools-scm
+  ];
+
+  nativeBuildInputs = [
     rustPlatform.cargoSetupHook
     cargo
     rustc
@@ -57,44 +57,48 @@ buildPythonPackage rec {
 
   buildInputs = lib.optionals stdenv.isDarwin [ libiconv ];
 
-  propagatedBuildInputs = [
+  dependencies = [
     typing-extensions
     typing-inspect
     pyyaml
   ];
 
   nativeCheckInputs = [
-    hypothesis
+    hypothesmith
     pytestCheckHook
+    ufmt
   ];
 
   preCheck = ''
-    # otherwise import libcst.native fails
-    cp build/lib.*/libcst/native.* libcst/
-
-    ${python.interpreter} -m libcst.codegen.generate visitors
-    ${python.interpreter} -m libcst.codegen.generate return_types
-
-    # Can't run all tests due to circular dependency on hypothesmith -> libcst
-    rm -r {libcst/tests,libcst/codegen/tests,libcst/m*/tests}
+    # import from $out instead
+    rm libcst/__init__.py
   '';
 
   disabledTests = [
-    # No files are generated
-    "test_codemod_formatter_error_input"
+    # FIXME package pyre-test
+    "TypeInferenceProviderTest"
+    # we'd need to run `python -m libcst.codegen.generate all` but shouldn't modify $out
+    "test_codegen_clean_visitor_functions"
   ];
 
+  # circular dependency on hypothesmith and ufmt
+  doCheck = false;
+
+  passthru.tests = {
+    pytest = libcst.overridePythonAttrs { doCheck = true; };
+  };
+
   pythonImportsCheck = [ "libcst" ];
 
-  meta = with lib; {
+  meta = {
     description = "Concrete Syntax Tree (CST) parser and serializer library for Python";
     homepage = "https://github.com/Instagram/libcst";
     changelog = "https://github.com/Instagram/LibCST/blob/v${version}/CHANGELOG.md";
-    license = with licenses; [
+    license = with lib.licenses; [
       mit
       asl20
       psfl
     ];
-    maintainers = [ ];
+    maintainers = with lib.maintainers; [ dotlambda ];
   };
 }