fix test suite (pytest changes in ExceptionInfo class)
diff --git a/tests/test_eigen.py b/tests/test_eigen.py
index 45f64ca..55d9351 100644
--- a/tests/test_eigen.py
+++ b/tests/test_eigen.py
@@ -679,10 +679,10 @@
     # These should still fail (incompatible dimensions):
     with pytest.raises(TypeError) as excinfo:
         m.iss1105_row(np.ones((7, 1)))
-    assert "incompatible function arguments" in str(excinfo)
+    assert "incompatible function arguments" in str(excinfo.value)
     with pytest.raises(TypeError) as excinfo:
         m.iss1105_col(np.ones((1, 7)))
-    assert "incompatible function arguments" in str(excinfo)
+    assert "incompatible function arguments" in str(excinfo.value)
 
 
 def test_custom_operator_new():
diff --git a/tests/test_local_bindings.py b/tests/test_local_bindings.py
index b3dc361..b380376 100644
--- a/tests/test_local_bindings.py
+++ b/tests/test_local_bindings.py
@@ -220,7 +220,7 @@
     c, d = m.MixGL2(3), cm.MixGL2(4)
     with pytest.raises(TypeError) as excinfo:
         m.get_gl_value(c)
-    assert "incompatible function arguments" in str(excinfo)
+    assert "incompatible function arguments" in str(excinfo.value)
     with pytest.raises(TypeError) as excinfo:
         m.get_gl_value(d)
-    assert "incompatible function arguments" in str(excinfo)
+    assert "incompatible function arguments" in str(excinfo.value)
diff --git a/tests/test_methods_and_attributes.py b/tests/test_methods_and_attributes.py
index 86b2c3b..f1c862b 100644
--- a/tests/test_methods_and_attributes.py
+++ b/tests/test_methods_and_attributes.py
@@ -100,32 +100,32 @@
 
     with pytest.raises(AttributeError) as excinfo:
         dummy = instance.def_property_writeonly  # noqa: F841 unused var
-    assert "unreadable attribute" in str(excinfo)
+    assert "unreadable attribute" in str(excinfo.value)
 
     instance.def_property_writeonly = 4
     assert instance.def_property_readonly == 4
 
     with pytest.raises(AttributeError) as excinfo:
         dummy = instance.def_property_impossible  # noqa: F841 unused var
-    assert "unreadable attribute" in str(excinfo)
+    assert "unreadable attribute" in str(excinfo.value)
 
     with pytest.raises(AttributeError) as excinfo:
         instance.def_property_impossible = 5
-    assert "can't set attribute" in str(excinfo)
+    assert "can't set attribute" in str(excinfo.value)
 
 
 def test_static_properties():
     assert m.TestProperties.def_readonly_static == 1
     with pytest.raises(AttributeError) as excinfo:
         m.TestProperties.def_readonly_static = 2
-    assert "can't set attribute" in str(excinfo)
+    assert "can't set attribute" in str(excinfo.value)
 
     m.TestProperties.def_readwrite_static = 2
     assert m.TestProperties.def_readwrite_static == 2
 
     with pytest.raises(AttributeError) as excinfo:
         dummy = m.TestProperties.def_writeonly_static  # noqa: F841 unused var
-    assert "unreadable attribute" in str(excinfo)
+    assert "unreadable attribute" in str(excinfo.value)
 
     m.TestProperties.def_writeonly_static = 3
     assert m.TestProperties.def_readonly_static == 3
@@ -133,14 +133,14 @@
     assert m.TestProperties.def_property_readonly_static == 3
     with pytest.raises(AttributeError) as excinfo:
         m.TestProperties.def_property_readonly_static = 99
-    assert "can't set attribute" in str(excinfo)
+    assert "can't set attribute" in str(excinfo.value)
 
     m.TestProperties.def_property_static = 4
     assert m.TestProperties.def_property_static == 4
 
     with pytest.raises(AttributeError) as excinfo:
         dummy = m.TestProperties.def_property_writeonly_static
-    assert "unreadable attribute" in str(excinfo)
+    assert "unreadable attribute" in str(excinfo.value)
 
     m.TestProperties.def_property_writeonly_static = 5
     assert m.TestProperties.def_property_static == 5
@@ -158,7 +158,7 @@
 
     with pytest.raises(AttributeError) as excinfo:
         dummy = instance.def_property_writeonly_static  # noqa: F841 unused var
-    assert "unreadable attribute" in str(excinfo)
+    assert "unreadable attribute" in str(excinfo.value)
 
     instance.def_property_writeonly_static = 4
     assert instance.def_property_static == 4
diff --git a/tests/test_smart_ptr.py b/tests/test_smart_ptr.py
index 0a3bb58..c662704 100644
--- a/tests/test_smart_ptr.py
+++ b/tests/test_smart_ptr.py
@@ -272,7 +272,8 @@
     instance = m.HeldByDefaultHolder()
     with pytest.raises(RuntimeError) as excinfo:
         m.HeldByDefaultHolder.load_shared_ptr(instance)
-    assert "Unable to load a custom holder type from a default-holder instance" in str(excinfo)
+    assert "Unable to load a custom holder type from a " \
+           "default-holder instance" in str(excinfo.value)
 
 
 def test_shared_ptr_gc():