diff --git a/craft_parts/errors.py b/craft_parts/errors.py
index 03c8b083b..781b04d2a 100644
--- a/craft_parts/errors.py
+++ b/craft_parts/errors.py
@@ -513,27 +513,28 @@ def __init__(
     def details(self) -> str | None:
         """Further details on the error.
 
-        Discards all trace lines that come before the last-executed script line
+        Displays the last three trace lines from the error output.
         """
-        with contextlib.closing(StringIO()) as details_io:
-            if self.stderr is None:
-                return None
-
-            stderr = self.stderr.decode("utf-8", errors="replace")
-            stderr_lines = stderr.split("\n")
-            # Find the final command captured in the logs
-            last_command = None
-            for idx, line in enumerate(reversed(stderr_lines)):
-                if line.startswith("+"):
-                    last_command = len(stderr_lines) - idx - 1
+        if self.stderr is None:
+            return None
+
+        stderr = self.stderr.decode("utf-8", errors="replace")
+        stderr_lines = list(filter(lambda x: x, stderr.split("\n")))
+
+        # Find the third trace output line
+        anchor_line = 0
+        traced_lines_to_display = 3
+        count = 0
+        for idx, line in enumerate(reversed(stderr_lines)):
+            if line.startswith("+"):
+                count += 1
+                if count > traced_lines_to_display:
+                    anchor_line = -idx
                     break
-            else:
-                # Fallback to printing the whole log
-                last_command = 0
 
-            for line in stderr_lines[last_command:]:
-                if line:
-                    details_io.write(f"\n:: {line}")
+        with contextlib.closing(StringIO()) as details_io:
+            for line in stderr_lines[anchor_line:]:
+                details_io.write(f"\n:: {line}")
 
             return details_io.getvalue()
 
diff --git a/craft_parts/plugins/base.py b/craft_parts/plugins/base.py
index 02ab54913..948e0e8cd 100644
--- a/craft_parts/plugins/base.py
+++ b/craft_parts/plugins/base.py
@@ -1,6 +1,6 @@
 # -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
 #
-# Copyright 2020-2024 Canonical Ltd.
+# Copyright 2020-2025 Canonical Ltd.
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -164,7 +164,7 @@ def _get_find_python_interpreter_commands(self) -> list[str]:
             # look for python3.10
             basename=$(basename $(readlink -f ${{PARTS_PYTHON_VENV_INTERP_PATH}}))
             echo Looking for a Python interpreter called \\"${{basename}}\\" in the payload...
-            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null)
+            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null || true)
 
             if [ -n "$payload_python" ]; then
                 # We found a provisioned interpreter, use it.
@@ -179,12 +179,12 @@ def _get_find_python_interpreter_commands(self) -> list[str]:
                 fi
             else
                 # Otherwise use what _get_system_python_interpreter() told us.
-                echo "Python interpreter not found in payload."
+                echo "Python interpreter not found in payload." >&2
                 symlink_target="{python_interpreter}"
             fi
 
             if [ -z "$symlink_target" ]; then
-                echo "No suitable Python interpreter found, giving up."
+                echo "No suitable Python interpreter found, giving up." >&2
                 exit 1
             fi
 
diff --git a/docs/reference/changelog.rst b/docs/reference/changelog.rst
index fc2c62f6f..bbe13f56c 100644
--- a/docs/reference/changelog.rst
+++ b/docs/reference/changelog.rst
@@ -2,6 +2,13 @@
 Changelog
 *********
 
+X.Y.Z ()
+------------------
+
+Bug fixes:
+
+- Fix handling and propagation of Python plugin error messages.
+
 2.6.1 (2025-02-12)
 ------------------
 
@@ -11,7 +18,6 @@ Bug fixes:
 - Fix Jdeps parameter ordering in the 
   :ref:`jlink plugin<craft_parts_jlink_plugin>`.
 
-
 2.3.1 (2025-02-07)
 ------------------
 
diff --git a/pyproject.toml b/pyproject.toml
index 26f75cbfa..c0b3b0a23 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -75,7 +75,7 @@ dev = [  # TODO: Remove this once we've switched CI to uv
     # Testing
     "hypothesis",
     "jsonschema",
-    "pytest-check",
+    "pytest-check<2.5.0",
     "pytest-subprocess",
     "requests-mock",
 
diff --git a/tests/integration/executor/test_errors.py b/tests/integration/executor/test_errors.py
index 7f69e2235..29896c699 100644
--- a/tests/integration/executor/test_errors.py
+++ b/tests/integration/executor/test_errors.py
@@ -74,6 +74,7 @@ def test_plugin_build_errors(new_dir, partitions):
         """\
             Failed to run the build script for part 'foo'.
 
+            :: + go mod download all
             :: + go install -p 1 ./...
             :: # example.com/hello
             :: ./hello.go:9:9: undefined: fmt.Printfs
diff --git a/tests/integration/plugins/test_poetry.py b/tests/integration/plugins/test_poetry.py
index 49998b515..310eddcde 100644
--- a/tests/integration/plugins/test_poetry.py
+++ b/tests/integration/plugins/test_poetry.py
@@ -241,21 +241,39 @@ def _get_system_python_interpreter(self) -> str | None:
     )
     actions = lf.plan(Step.PRIME)
 
+    expected_error_text = textwrap.dedent(
+        """\
+        + '[' -z '' ']'
+        + echo 'No suitable Python interpreter found, giving up.'
+        No suitable Python interpreter found, giving up.
+        + exit 1
+        """
+    )
+
     out = pathlib.Path("out.txt")
-    with out.open(mode="w") as outfile, pytest.raises(errors.PluginBuildError):
+    err = pathlib.Path("err.txt")
+    with (
+        out.open(mode="w") as outfile,
+        err.open(mode="w") as errfile,
+        pytest.raises(errors.PluginBuildError) as exc_info,
+    ):
         with lf.action_executor() as ctx:
-            ctx.execute(actions, stdout=outfile)
+            ctx.execute(actions, stdout=outfile, stderr=errfile)
+
+    assert exc_info.value.stderr is not None
+    assert expected_error_text in exc_info.value.stderr.decode()
 
     output = out.read_text()
     expected_text = textwrap.dedent(
         f"""\
         Looking for a Python interpreter called "{real_basename}" in the payload...
-        Python interpreter not found in payload.
-        No suitable Python interpreter found, giving up.
         """
     )
     assert expected_text in output
 
+    output = err.read_text()
+    assert expected_error_text in output
+
 
 def test_find_payload_python_good_version(new_dir, partitions, parts_dict, poetry_part):
     """Test that the build succeeds if a payload interpreter is needed, and it's
diff --git a/tests/integration/plugins/test_python.py b/tests/integration/plugins/test_python.py
index 48e17af34..705f41efb 100644
--- a/tests/integration/plugins/test_python.py
+++ b/tests/integration/plugins/test_python.py
@@ -321,21 +321,39 @@ def _get_system_python_interpreter(self) -> str | None:
     )
     actions = lf.plan(Step.PRIME)
 
+    expected_error_text = textwrap.dedent(
+        """\
+        + '[' -z '' ']'
+        + echo 'No suitable Python interpreter found, giving up.'
+        No suitable Python interpreter found, giving up.
+        + exit 1
+        """
+    )
+
     out = Path("out.txt")
-    with out.open(mode="w") as outfile, pytest.raises(errors.PluginBuildError):
+    err = Path("err.txt")
+    with (
+        out.open(mode="w") as outfile,
+        err.open(mode="w") as errfile,
+        pytest.raises(errors.PluginBuildError) as exc_info,
+    ):
         with lf.action_executor() as ctx:
-            ctx.execute(actions, stdout=outfile)
+            ctx.execute(actions, stdout=outfile, stderr=errfile)
+
+    assert exc_info.value.stderr is not None
+    assert expected_error_text in exc_info.value.stderr.decode()
 
     output = out.read_text()
     expected_text = textwrap.dedent(
         f"""\
         Looking for a Python interpreter called "{real_basename}" in the payload...
-        Python interpreter not found in payload.
-        No suitable Python interpreter found, giving up.
         """
     )
     assert expected_text in output
 
+    output = err.read_text()
+    assert expected_error_text in output
+
 
 def test_find_payload_python_good_version(new_dir, partitions):
     """Test that the build succeeds if a payload interpreter is needed, and it's
diff --git a/tests/unit/plugins/test_base.py b/tests/unit/plugins/test_base.py
index 3dacf4445..3c458c4e8 100644
--- a/tests/unit/plugins/test_base.py
+++ b/tests/unit/plugins/test_base.py
@@ -1,6 +1,6 @@
 # -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
 #
-# Copyright 2021-2023 Canonical Ltd.
+# Copyright 2021-2025 Canonical Ltd.
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -146,7 +146,7 @@ def test_python_get_find_python_interpreter_commands(
             # look for python3.10
             basename=$(basename $(readlink -f ${{PARTS_PYTHON_VENV_INTERP_PATH}}))
             echo Looking for a Python interpreter called \\"${{basename}}\\" in the payload...
-            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null)
+            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null || true)
 
             if [ -n "$payload_python" ]; then
                 # We found a provisioned interpreter, use it.
@@ -161,12 +161,12 @@ def test_python_get_find_python_interpreter_commands(
                 fi
             else
                 # Otherwise use what _get_system_python_interpreter() told us.
-                echo "Python interpreter not found in payload."
+                echo "Python interpreter not found in payload." >&2
                 symlink_target="$(readlink -f "$(which "${{PARTS_PYTHON_INTERPRETER}}")")"
             fi
 
             if [ -z "$symlink_target" ]; then
-                echo "No suitable Python interpreter found, giving up."
+                echo "No suitable Python interpreter found, giving up." >&2
                 exit 1
             fi
 
@@ -238,7 +238,7 @@ def test_python_get_build_commands(new_dir, python_plugin: FooPythonPlugin):
             # look for python3.10
             basename=$(basename $(readlink -f ${{PARTS_PYTHON_VENV_INTERP_PATH}}))
             echo Looking for a Python interpreter called \\"${{basename}}\\" in the payload...
-            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null)
+            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null || true)
 
             if [ -n "$payload_python" ]; then
                 # We found a provisioned interpreter, use it.
@@ -253,12 +253,12 @@ def test_python_get_build_commands(new_dir, python_plugin: FooPythonPlugin):
                 fi
             else
                 # Otherwise use what _get_system_python_interpreter() told us.
-                echo "Python interpreter not found in payload."
+                echo "Python interpreter not found in payload." >&2
                 symlink_target="$(readlink -f "$(which "${{PARTS_PYTHON_INTERPRETER}}")")"
             fi
 
             if [ -z "$symlink_target" ]; then
-                echo "No suitable Python interpreter found, giving up."
+                echo "No suitable Python interpreter found, giving up." >&2
                 exit 1
             fi
 
diff --git a/tests/unit/plugins/test_base_python.py b/tests/unit/plugins/test_base_python.py
index 8bc34e36c..3cae85673 100644
--- a/tests/unit/plugins/test_base_python.py
+++ b/tests/unit/plugins/test_base_python.py
@@ -1,6 +1,6 @@
 # -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
 #
-# Copyright 2024 Canonical Ltd.
+# Copyright 2025 Canonical Ltd.
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -72,7 +72,7 @@ def get_python_build_commands(
             # look for python3.10
             basename=$(basename $(readlink -f ${{PARTS_PYTHON_VENV_INTERP_PATH}}))
             echo Looking for a Python interpreter called \\"${{basename}}\\" in the payload...
-            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null)
+            payload_python=$(find "$install_dir" "$stage_dir" -type f -executable -name "${{basename}}" -print -quit 2>/dev/null || true)
 
             if [ -n "$payload_python" ]; then
                 # We found a provisioned interpreter, use it.
@@ -87,12 +87,12 @@ def get_python_build_commands(
                 fi
             else
                 # Otherwise use what _get_system_python_interpreter() told us.
-                echo "Python interpreter not found in payload."
+                echo "Python interpreter not found in payload." >&2
                 symlink_target="$(readlink -f "$(which "${{PARTS_PYTHON_INTERPRETER}}")")"
             fi
 
             if [ -z "$symlink_target" ]; then
-                echo "No suitable Python interpreter found, giving up."
+                echo "No suitable Python interpreter found, giving up." >&2
                 exit 1
             fi
 
diff --git a/tests/unit/utils/test_process.py b/tests/unit/utils/test_process.py
index 84b29ad69..a02549403 100644
--- a/tests/unit/utils/test_process.py
+++ b/tests/unit/utils/test_process.py
@@ -33,7 +33,7 @@
 
 @pytest.mark.parametrize(("out", "err"), _RUN_TEST_CASES)
 def test_run(out, err):
-    result = process.run(["/usr/bin/sh", "-c", f"echo {out};sleep 0;echo {err} >&2"])
+    result = process.run(["/usr/bin/sh", "-c", f"echo {out};sleep 0.1;echo {err} >&2"])
     assert result.returncode == 0
     assert result.stdout == (out + "\n").encode()
     assert result.stderr == (err + "\n").encode()
@@ -82,7 +82,7 @@ def read(conn: socket.socket, _mask: int) -> None:
         [
             "/usr/bin/sh",
             "-c",
-            f"echo {out};sleep 0;echo {err} >&2; echo -n {out}|socat - UNIX-CONNECT:{new_dir}/test.socket",
+            f"echo {out};sleep 0.1;echo {err} >&2; echo -n {out}|socat - UNIX-CONNECT:{new_dir}/test.socket",
         ],
         selector=selector,
     )