Close #19746: expose unittest discovery errors on TestLoader.errors
This makes it possible to examine the errors from unittest discovery
without executing the test suite - important when the test suite may
be very large, or when enumerating the test ids from a test suite.
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index 1c2d8f6..2bd75b8 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -1552,6 +1552,20 @@
:data:`unittest.defaultTestLoader`. Using a subclass or instance, however,
allows customization of some configurable properties.
+ :class:`TestLoader` objects have the following attributes:
+
+
+ .. attribute:: errors
+
+ A list of the non-fatal errors encountered while loading tests. Not reset
+ by the loader at any point. Fatal errors are signalled by the relevant
+ a method raising an exception to the caller. Non-fatal errors are also
+ indicated by a synthetic test that will raise the original error when
+ run.
+
+ .. versionadded:: 3.5
+
+
:class:`TestLoader` objects have the following methods: