[debian-mysql] Bug#920365: mariadb_config: improve cross compilation support

[Christoph Berg]

Re: Helmut Grohne 2019-01-24 <20190124190511.GA30035 at alf.mars>
> This is very unfortunate and we've had the exact same situation with
> postgresql/pg_config. Then Christoph (Cced) came up with a crazy idea:
> Run pg_config at build time, capture all of its output and generate a
> shell script from it. Then he turned the packaged pg_config into a perl
> script. How does that help? When running the host architecture
> pg_config, it is run via /usr/bin/perl, which is a build architecture
> executable. The "Exec format error" goes away. One gets the right
> results.

Fwiw, the PostgreSQL hack is there: https://salsa.debian.org/postgresql/postgresql/blob/11/debian/pg_config.pl

The __DATA__ section there is a stub, it get replaced by the real data
at build time.

https://salsa.debian.org/postgresql/postgresql/blob/11/debian/rules#L187-191

Christoph