Issue #10372: Import the warnings module only after the IO library is
initialized, so as to avoid bootstrap issues with the '-W' option.
diff --git a/Lib/test/test_warnings.py b/Lib/test/test_warnings.py
index 52b9dbe..111ff79 100644
--- a/Lib/test/test_warnings.py
+++ b/Lib/test/test_warnings.py
@@ -6,6 +6,7 @@
import unittest
import subprocess
from test import support
+from test.script_helper import assert_python_ok
from test import warning_tests
@@ -393,6 +394,22 @@
self.module._setoption('error::Warning::0')
self.assertRaises(UserWarning, self.module.warn, 'convert to error')
+ def test_improper_option(self):
+ # Same as above, but check that the message is printed out when
+ # the interpreter is executed. This also checks that options are
+ # actually parsed at all.
+ rc, out, err = assert_python_ok("-Wxxx", "-c", "pass")
+ self.assertIn(b"Invalid -W option ignored: invalid action: 'xxx'", err)
+
+ def test_warnings_bootstrap(self):
+ # Check that the warnings module does get loaded when -W<some option>
+ # is used (see issue #10372 for an example of silent bootstrap failure).
+ rc, out, err = assert_python_ok("-Wi", "-c",
+ "import sys; sys.modules['warnings'].warn('foo', RuntimeWarning)")
+ # '-Wi' was observed
+ self.assertFalse(out.strip())
+ self.assertNotIn(b'RuntimeWarning', err)
+
class CWCmdLineTests(BaseTest, WCmdLineTests):
module = c_warnings
diff --git a/Misc/NEWS b/Misc/NEWS
index 5cd6647..7dc9b6c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
Core and Builtins
-----------------
+- Issue #10372: Import the warnings module only after the IO library is
+ initialized, so as to avoid bootstrap issues with the '-W' option.
+
- Issue #10293: Remove obsolete field in the PyMemoryView structure,
unused undocumented value PyBUF_SHADOW, and strangely-looking code in
PyMemoryView_GetContiguous.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 8b1e61a..784558c 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -299,19 +299,21 @@
if (install_sigs)
initsigs(); /* Signal handling stuff, including initintr() */
- /* Initialize warnings. */
- if (PySys_HasWarnOptions()) {
- PyObject *warnings_module = PyImport_ImportModule("warnings");
- if (!warnings_module)
- PyErr_Clear();
- Py_XDECREF(warnings_module);
- }
-
initmain(); /* Module __main__ */
if (initstdio() < 0)
Py_FatalError(
"Py_Initialize: can't initialize sys standard streams");
+ /* Initialize warnings. */
+ if (PySys_HasWarnOptions()) {
+ PyObject *warnings_module = PyImport_ImportModule("warnings");
+ if (warnings_module == NULL) {
+ fprintf(stderr, "'import warnings' failed; traceback:\n");
+ PyErr_Print();
+ }
+ Py_XDECREF(warnings_module);
+ }
+
if (!Py_NoSiteFlag)
initsite(); /* Module site */
}