Issue with GitHub Security Scanning: gmtime

[AlexanderLanin]

Description

I've just attempted to enable Security Scanning via https://github.com/AlexanderLanin/ccache/pull/4/files
I expected none or a few warnings.
I did not expect warnings from doctest.

The warning you can see here:
https://github.com/AlexanderLanin/ccache/security/code-scanning/1?query=ref%3Arefs%2Fpull%2F4%2Fhead

Steps to reproduce

Probably the same can be achieved by enabling security scanning on doctest itself, although I have not attempted it.
See https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/enabling-code-scanning-for-a-repository

Extra information

I'm not quite sure how to avoid the warning, but it seems reasonable to attempt to do so, since everyone trying to enable security scanning will get a warning from doctest. The recommendation to use gmtime_r seems overly simplistic as that one is introduced in C++20. On very first glance it is available on all major systems except older Visual Studio compilers.

[nlohmann]

I see the same warning in nlohmann/json, see report:
https://github.com/nlohmann/json/security/code-scanning/1?query=ref%3Arefs%2Fheads%2Fdevelop

Would be great if this could be fixed.

[onqtam]

I'll take a look at this by the end of December. Btw the link is broken

[nlohmann]

Oh, apparently, these links are somehow private.

[onqtam]

Fixed in the dev branch - will release a new version before the end of the year.

[nlohmann]

Awesome, thanks!