Re: [PATCH 1/1] git-compat-util: add a test balloon for C99 support

> +#if __STDC_VERSION__ - 0 < 199901L
> +/*
> + * Git is in a testing period for mandatory C99 support in the compiler.  If
> + * your compiler is reasonably recent, you can try to enable C99 support (or,
> + * for MSVC, C11 support).  If you encounter a problem and can't enable C99
> + * support with your compiler and don't have access to one with this support,
> + * such as GCC or Clang, you can remove this #if directive, but please report
> + * the details of your system to git@vger.kernel.org.
> + */
> +#error "Required C99 support is in a test phase.  Please see git-compat-util.h for more details."