Thanks for the change. I don't understand why debug build uses 7x more stack memory, but I trust your tests https://bugs.python.org/issue38852#msg357266 :-)

@xdegaye: Do you want to backport the change to Python 3.7 and/or 3.8?

@vstinner

I don't understand why debug build uses 7x more stack memory

In the initial post of issue https://bugs.python.org/issue18049, Ronald considers that it is the -O0 optimisation level in debug builds that causes this increase in stack memory usage. The commits that fix this issue do not use the #ifdef PY_DEBUG conditional suggested by Stéphane in the third post because, as I understand it, it is considered that "users could also build with CFLAGS set to -O0 without using --with-pydebug".

BTW in both android and OSX cases it seems that it is clang with debug builds that causes the problem. See issue https://bugs.python.org/issue14184, the initial change in stack size on OSX.

Do you want to backport the change to Python 3.7 and/or 3.8?

Since only debug builds are concerned with this change and android is not officially supported, I think backports are not necessary.

In the initial post of issue https://bugs.python.org/issue18049, Ronald considers that it is the -O0 optimisation level in debug builds that causes this increase in stack memory usage.

Ah yes, that makes sense.

Since only debug builds are concerned with this change and android is not officially supported, I think backports are not necessary.

Ok, I'm fine with that.