bpo-34602: Avoid failures setting macOS stack resource limit (GH-14546)

Under some conditions the earlier fix for bpo-18075, "Infinite recursion
tests triggering a segfault on Mac OS X", now causes failures on macOS
when attempting to change stack limit with resource.setrlimit
resource.RLIMIT_STACK, like regrtest does when running the test suite.
The reverted change had specified a non-default stack size when linking
the python executable on macOS.  As of macOS 10.14.4, the previous
code causes a hard failure when running tests, although similar
failures had been seen under some conditions under some earlier
systems.  Reverting the change to the interpreter stack size at link
time helped for release builds but caused some tests to fail when
built --with-pydebug.  Try the opposite approach: continue to build
the interpreter with an increased stack size on macOS and remove
the failing setrlimit call in regrtest initialization.  This will
definitely avoid the resource.RLIMIT_STACK error and should have
no, or fewer, side effects.
(cherry picked from commit 5bbbc733e6cc0804f19b071944af8d4719e26ae6)

Co-authored-by: Ned Deily <nad@python.org>

diff --git a/Lib/test/libregrtest/setup.py b/Lib/test/libregrtest/setup.py
index fb5ac350cd084743d0e31d24b0b5f19ad02a7d5e..1e0eac3b0fbbd103d5d2ad3ec700b24a634e46b4 100644 (file)
--- a/Lib/test/libregrtest/setup.py
+++ b/Lib/test/libregrtest/setup.py
@@ -58,22 +58,6 @@ def setup_tests(ns):
         if getattr(module, '__file__', None):
             module.__file__ = os.path.abspath(module.__file__)
 
-    # MacOSX (a.k.a. Darwin) has a default stack size that is too small
-    # for deeply recursive regular expressions.  We see this as crashes in
-    # the Python test suite when running test_re.py and test_sre.py.  The
-    # fix is to set the stack limit to 2048.
-    # This approach may also be useful for other Unixy platforms that
-    # suffer from small default stack limits.
-    if sys.platform == 'darwin':
-        try:
-            import resource
-        except ImportError:
-            pass
-        else:
-            soft, hard = resource.getrlimit(resource.RLIMIT_STACK)
-            newsoft = min(hard, max(soft, 1024*2048))
-            resource.setrlimit(resource.RLIMIT_STACK, (newsoft, hard))
-
     if ns.huntrleaks:
         unittest.BaseTestSuite._cleanup = False
 

diff --git a/Misc/NEWS.d/next/macOS/2019-07-02-01-06-47.bpo-34602.10d4wl.rst b/Misc/NEWS.d/next/macOS/2019-07-02-01-06-47.bpo-34602.10d4wl.rst
new file mode 100644 (file)
index 0000000..c50ac63
--- /dev/null
+++ b/Misc/NEWS.d/next/macOS/2019-07-02-01-06-47.bpo-34602.10d4wl.rst
@@ -0,0 +1,4 @@
+Avoid test suite failures on macOS by no longer calling resource.setrlimit
+to increase the process stack size limit at runtime.  The runtime change is
+no longer needed since the interpreter is being built with a larger default
+stack size.

diff --git a/configure b/configure
index b606fc808c17c18a13aafddc047cb4c6137104c1..6e7f277bace9b330155dc16a38d58eb7635d7a43 100755 (executable)
--- a/configure
+++ b/configure
@@ -9524,6 +9524,12 @@ then
        # -u libsys_s pulls in all symbols in libsys
        Darwin/*)
                LINKFORSHARED="$extra_undefs -framework CoreFoundation"
+
+               # Issue #18075: the default maximum stack size (8MBytes) is too
+               # small for the default recursion limit. Increase the stack size
+               # to ensure that tests don't crash
+               LINKFORSHARED="-Wl,-stack_size,1000000 $LINKFORSHARED"
+
                if test "$enable_framework"
                then
                        LINKFORSHARED="$LINKFORSHARED "'$(PYTHONFRAMEWORKDIR)/Versions/$(VERSION)/$(PYTHONFRAMEWORK)'

diff --git a/configure.ac b/configure.ac
index 3d589ac25891676947c2bfffc9da038eebcf7dae..324ce0bd99a9c3f5229de6baefb069b41d1dce38 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -2682,6 +2682,12 @@ then
        # -u libsys_s pulls in all symbols in libsys
        Darwin/*)
                LINKFORSHARED="$extra_undefs -framework CoreFoundation"
+
+               # Issue #18075: the default maximum stack size (8MBytes) is too
+               # small for the default recursion limit. Increase the stack size
+               # to ensure that tests don't crash
+               LINKFORSHARED="-Wl,-stack_size,1000000 $LINKFORSHARED"
+
                if test "$enable_framework"
                then
                        LINKFORSHARED="$LINKFORSHARED "'$(PYTHONFRAMEWORKDIR)/Versions/$(VERSION)/$(PYTHONFRAMEWORK)'