Python 3.14 stack overflow detection is incompatible with C++ Boost make_fcontext() coroutines

Python 3.14 introduced a new stack overflow detection mecanism: InternalDocs/stack_protection.md (#130396).

The KiCad application uses C++ Boost make_fcontext() coroutines which runs coroutine in their own stack.

Code example from fcontext doc:

// context-function
void f(intptr);

// creates a new stack
std::size_t size = 8192;
void* sp(std::malloc(size));

// context fc uses f() as context function
// fcontext_t is placed on top of context stack
// a pointer to fcontext_t is returned
fcontext_t fc(make_fcontext(sp,size,f));

_Py_InitializeRecursionLimits() is called in the main thread, whereas _Py_CheckRecursiveCall() is called for the first time in a coroutine (make_fcontext()).

Problem: Python detects a stack overflow because it's not aware that the stack base address and size changed when make_fcontext() was called.

pthread functions such as pthread_attr_getguardsize() are incompatible with make_fcontext().

cc @markshannon

Linked PRs

• gh-139667
• gh-139668
• gh-141551
• gh-141661
• gh-141711
• gh-141892
• gh-141944

从 InternalDocs/stack_protection.md 开始，然后跟踪来自 Boost make_fcontext() coroutine 的 _Py_InitializeRecursionLimits() 和第一次 _Py_CheckRecursiveCall()。查看链接的 PR，了解当前的方向，以及 stack-base 和 size 的转换是否已经得到处理；完成的标准是 coroutine stack 不再触发错误的 stack-overflow 检测。