SIGSTKSZ is not an integral constant with libc6 2.34

[migmolper]

Describe the bug
Updated versions of Ubuntu (21.10 and superiors) installed libc6 (glibc) 2.34. SIGSTKSZ is now no longer constant, and can’t be used directly to define array sizes. According to documentation:

"The constant SIGSTKSZ is defined to be large enough to cover the usual size requirements for an alternate signal stack".

See similar PR's in other people's codes:

• doctest git
• json git

And this is a proposed fix to the bug:

• json git

Affected file in the code:

• mpm/external/catch.hpp

Any thoughts @bodhinandach ?

To Reproduce
These are my machine specifications: "Ubuntu 22.04 LTS" and "gcc 11.2.0"

Screenshots

[bodhinandach]

Is this related to the testing? Let me have a look at it this week. Let's discuss this on Friday.

[bodhinandach]

@migmolper How are we dealing with this one?

[migmolper]

We are using this:

/*******************/

#include
#if defined(_SC_SIGSTKSZ_SOURCE) || defined(_GNU_SOURCE)
// on glibc > 2.33 this is no longer constant, see
// https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS;h=85e84fe53699fe9e392edffa993612ce08b2954a;hb=HEAD
static constexpr std::size_t sigStackSize = 32768;
#else
static constexpr std::size_t sigStackSize =
32768 >= SIGSTKSZ ? 32768 : SIGSTKSZ;
#endif

/*******************/

And then substitute SIGSTKSZ by sigStackSize

[bodhinandach]

This runs the test ok in the newer version of Linux?