Add details to error message for junit (#7390)

Co-authored-by: Bruno Oliveira <nicoddemus@gmail.com>

changelog/7385.improvement.rst

@@ -0,0 +1,13 @@
+``--junitxml`` now includes the exception cause in the ``message`` XML attribute for failures during setup and teardown.
+
+Previously:
+
+.. code-block:: xml
+
+    <error message="test setup failure">
+
+Now:
+
+.. code-block:: xml
+
+    <error message="failed on setup with &quot;ValueError: Some error during setup&quot;">

src/_pytest/junitxml.py

@@ -236,10 +236,16 @@ class _NodeReporter:
         self._add_simple(Junit.skipped, "collection skipped", report.longrepr)
 
     def append_error(self, report: TestReport) -> None:
-        if report.when == "teardown":
+        assert report.longrepr is not None
-            msg = "test teardown failure"
+        if getattr(report.longrepr, "reprcrash", None) is not None:
+            reason = report.longrepr.reprcrash.message
         else:
-            msg = "test setup failure"
+            reason = str(report.longrepr)
+
+        if report.when == "teardown":
+            msg = 'failed on teardown with "{}"'.format(reason)
+        else:
+            msg = 'failed on setup with "{}"'.format(reason)
         self._add_simple(Junit.error, msg, report.longrepr)
 
     def append_skipped(self, report: TestReport) -> None:

testing/test_junitxml.py

@@ -266,7 +266,7 @@ class TestPython:
 
             @pytest.fixture
             def arg(request):
-                raise ValueError()
+                raise ValueError("Error reason")
             def test_function(arg):
                 pass
         """
@@ -278,7 +278,7 @@ class TestPython:
         tnode = node.find_first_by_tag("testcase")
         tnode.assert_attr(classname="test_setup_error", name="test_function")
         fnode = tnode.find_first_by_tag("error")
-        fnode.assert_attr(message="test setup failure")
+        fnode.assert_attr(message='failed on setup with "ValueError: Error reason"')
         assert "ValueError" in fnode.toxml()
 
     @parametrize_families
@@ -290,7 +290,7 @@ class TestPython:
             @pytest.fixture
             def arg():
                 yield
-                raise ValueError()
+                raise ValueError('Error reason')
             def test_function(arg):
                 pass
         """
@@ -301,7 +301,7 @@ class TestPython:
         tnode = node.find_first_by_tag("testcase")
         tnode.assert_attr(classname="test_teardown_error", name="test_function")
         fnode = tnode.find_first_by_tag("error")
-        fnode.assert_attr(message="test teardown failure")
+        fnode.assert_attr(message='failed on teardown with "ValueError: Error reason"')
         assert "ValueError" in fnode.toxml()
 
     @parametrize_families
@@ -328,7 +328,9 @@ class TestPython:
         fnode = first.find_first_by_tag("failure")
         fnode.assert_attr(message="Exception: Call Exception")
         snode = second.find_first_by_tag("error")
-        snode.assert_attr(message="test teardown failure")
+        snode.assert_attr(
+            message='failed on teardown with "Exception: Teardown Exception"'
+        )
 
     @parametrize_families
     def test_skip_contains_name_reason(self, testdir, run_and_parse, xunit_family):