diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 323819b55..b64ba7faf 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -113,11 +113,15 @@ jobs:
           - tests/mock_vws/test_update_target.py::TestWidth
           - tests/mock_vws/test_update_target.py::TestInactiveProject
           - tests/mock_vws/test_requests_mock_usage.py
+          - tests/mock_vws/test_respx_mock_usage.py
+          - tests/mock_vws/test_target_validators.py
           - tests/mock_vws/test_flask_app_usage.py
           - tests/mock_vws/test_vumark_generation_api.py
           - tests/mock_vws/test_docker.py
           - README.rst
           - docs/source/basic-example.rst
+          - docs/source/httpx-example.rst
+          - ci/
 
     steps:
       - uses: actions/checkout@v6
diff --git a/ci/test_custom_linters.py b/ci/test_custom_linters.py
index c02fcacc6..0817a0896 100644
--- a/ci/test_custom_linters.py
+++ b/ci/test_custom_linters.py
@@ -1,15 +1,11 @@
 """Custom lint tests."""
 
 from pathlib import Path
-from typing import TYPE_CHECKING
 
 import pytest
 import yaml
 from beartype import beartype
 
-if TYPE_CHECKING:
-    from collections.abc import Iterable
-
 
 @beartype
 def _ci_patterns(*, repository_root: Path) -> set[str]:
@@ -23,32 +19,55 @@ def _ci_patterns(*, repository_root: Path) -> set[str]:
     return ci_patterns
 
 
+class _CollectPlugin:
+    """Pytest plugin that records collected node IDs."""
+
+    def __init__(self) -> None:
+        """Initialize an empty set of collected node IDs."""
+        self.nodeids: set[str] = set()
+
+    def pytest_collection_modifyitems(
+        self,
+        items: list[pytest.Item],
+    ) -> None:
+        """Record the node IDs of all collected items."""
+        self.nodeids.update(item.nodeid for item in items)
+
+
 @beartype
-def _tests_from_pattern(
-    *,
-    ci_pattern: str,
-    capsys: pytest.CaptureFixture[str],
-) -> set[str]:
-    """From a CI pattern, get all tests ``pytest`` would collect."""
-    # Clear the captured output.
-    capsys.readouterr()
-    tests: Iterable[str] = set()
-    pytest.main(
+def _tests_from_pattern(*, ci_pattern: str) -> set[str]:
+    """From a CI pattern, get all tests ``pytest`` would collect.
+
+    Uses a collection-hook plugin instead of parsing stdout: an in-process
+    ``pytest.main()`` installs its own output capture, so reading from
+    ``capsys`` would see an empty string and the test would pass vacuously.
+    """
+    plugin = _CollectPlugin()
+    exit_code = pytest.main(
         args=[
-            "-q",
             "--collect-only",
-            # If there are any warnings, these obscure the output.
+            # Disable pytest-retry to avoid:
+            # ```
+            # ValueError: no option named 'filtered_exceptions'
+            # ```
+            "-p",
+            "no:pytest-retry",
+            # Disable warnings to avoid many instances of:
+            # ```
+            # Unknown config option: retry_delay
+            # ```
             "--disable-warnings",
             ci_pattern,
         ],
+        plugins=[plugin],
+    )
+    # Fail loudly on collection errors (import failures, syntax errors, etc.)
+    # rather than silently using whatever items were captured before the
+    # crash.
+    assert exit_code == pytest.ExitCode.OK, (
+        f"Collection for {ci_pattern!r} failed with exit code {exit_code}."
     )
-    data = capsys.readouterr().out
-    for line in data.splitlines():
-        # We filter empty lines and lines which look like
-        # "9 tests collected in 0.01s".
-        if line and "collected in" not in line:
-            tests = {*tests, line}
-    return set(tests)
+    return plugin.nodeids
 
 
 def test_ci_patterns_valid(request: pytest.FixtureRequest) -> None:
@@ -60,31 +79,13 @@ def test_ci_patterns_valid(request: pytest.FixtureRequest) -> None:
     ci_patterns = _ci_patterns(repository_root=request.config.rootpath)
 
     for ci_pattern in ci_patterns:
-        collect_only_result = pytest.main(
-            args=[
-                "--collect-only",
-                ci_pattern,
-                # Disable pytest-retry to avoid:
-                # ```
-                # ValueError: no option named 'filtered_exceptions'
-                # ````
-                "-p",
-                "no:pytest-retry",
-                # Disable warnings to avoid many instances of:
-                # ```
-                # Unknown config option: retry_delay
-                # ```
-                "--disable-warnings",
-            ],
-        )
-
+        tests = _tests_from_pattern(ci_pattern=ci_pattern)
         message = f'"{ci_pattern}" does not match any tests.'
-        assert collect_only_result == 0, message
+        assert tests, message
 
 
 def test_tests_collected_once(
     *,
-    capsys: pytest.CaptureFixture[str],
     request: pytest.FixtureRequest,
 ) -> None:
     """Each test in the test suite is collected exactly once.
@@ -95,12 +96,9 @@ def test_tests_collected_once(
     tests_to_patterns: dict[str, set[str]] = {}
 
     for pattern in ci_patterns:
-        tests = _tests_from_pattern(ci_pattern=pattern, capsys=capsys)
+        tests = _tests_from_pattern(ci_pattern=pattern)
         for test in tests:
-            if test in tests_to_patterns:
-                tests_to_patterns[test].add(pattern)
-            else:
-                tests_to_patterns[test] = {pattern}
+            tests_to_patterns.setdefault(test, set()).add(pattern)
 
     for test_name, patterns in tests_to_patterns.items():
         message = (
@@ -110,6 +108,6 @@ def test_tests_collected_once(
         )
         assert len(patterns) == 1, message
 
-    all_tests = _tests_from_pattern(ci_pattern=".", capsys=capsys)
+    all_tests = _tests_from_pattern(ci_pattern=".")
     assert tests_to_patterns.keys() - all_tests == set()
     assert all_tests - tests_to_patterns.keys() == set()