diff --git a/docs/changelog/2332.bugfix.rst b/docs/changelog/2332.bugfix.rst
new file mode 100644
index 000000000..6c297563a
--- /dev/null
+++ b/docs/changelog/2332.bugfix.rst
@@ -0,0 +1,2 @@
+Fixed failing isolated_build because setuptools warning was captured
+in ``build_requires``. -- by :user:`zariiii9003`
diff --git a/src/tox/package/builder/isolated.py b/src/tox/package/builder/isolated.py
index b2cf05e06..1b3f6f491 100644
--- a/src/tox/package/builder/isolated.py
+++ b/src/tox/package/builder/isolated.py
@@ -145,5 +145,6 @@ def get_build_requires(build_info, package_venv, setup_dir):
             returnout=True,
             action=action,
             cwd=setup_dir,
+            capture_err=False,
         )
         return json.loads(result.split("\n")[-2])
diff --git a/src/tox/venv.py b/src/tox/venv.py
index 87e01656e..13235c8a9 100644
--- a/src/tox/venv.py
+++ b/src/tox/venv.py
@@ -583,6 +583,7 @@ def _pcall(
         ignore_ret=False,
         returnout=False,
         env=None,
+        capture_err=True,
     ):
         if env is None:
             env = self._get_os_environ(is_test_command=is_test_command)
@@ -618,6 +619,7 @@ def _pcall(
             ignore_ret=ignore_ret,
             returnout=returnout,
             report_fail=not is_test_command,
+            capture_err=capture_err,
         )
 
     def setupenv(self):