Re: [ulogd2 PATCH 03/10] build: use pkg-config or upstream M4 for mysql

[Duncan Roe <duncan_roe@optusnet.com.au>]

On Thu, Jan 06, 2022 at 11:15:31PM +0100, Jan Engelhardt wrote:
>
> On Thursday 2022-01-06 22:09, Jeremy Sowden wrote:
>
> >Recent versions of mariadb and mysql have supported pkg-config.
>
> (This made me read up on Stackexchange about exact rules for present
> perfect, only to find it is not neatly delineated.) IMO better to
> just use present. They (still) support pkg-config.
>
+  dnl Recent versions of MySQL and MariaDB include pkg-config support.
>
>
Suggest imperfect past tense, to match "recent versions" suggestion.

+  dnl Older versions included a mysql.m4 file which provided macros to
>
> "had included", as I don't see that m4 file anymore on my (mariadb) systems.
> (There are a few mysql-related m4 files in autoconf-archive,
> but that's not the same package as mysql/mariadb, I suppose.)
>
> >+    dnl The [MYSQL_CLIENT] macro calls [_MYSQL_CONFIG] to locate mysql_config.
> >+
> >+    _MYSQL_CONFIG
>
> One caveat of m4 macros is that they may be left unexpanded if not found,
> and it is up to the tarball producer to ensure the m4 macro is expanded.
> Over the years, I built the opinion that this is not always a nice experience
> to have.
>
> I would do away with _MYSQL_CONFIG and just attempt to run `mysql_config` out
> the blue. sh failing to execute mysql_config, or a compiler failing to find
> mysql.h as part of AC_CHECK_HEADER is a nicer experience than _MYSQL_CONFIG
> being left accidentally unexpanded.
>
> >+      dnl Some distro's don't put mysql_config in the same package as the
>
> distros
>