Bug#971604: qtbase-opensource-src FTCBFS: fails finding mysql

[Helmut Grohne <helmut@subdivi.de>]

Source: qtbase-opensource-src
Version: 5.14.2+dfsg-6
Tags: patch upstream
User: debian-cross@lists.debian.org
Usertags: ftcbfs

We did have a few stabs at making qtbase-opensource-src cross buildable
already. At some point, it was running into an Exec format error when
running mysql_config and we concluded that this should be fixed on the
mariadb side. That's not gonna happen, because doing so would break
cross building mariadb. What needs to happens is that the world stops
using mysql_config. As bad as this sounds, the solution is quite simple,
because the building blocks are already included: pkg-config and
mysqlclient.pc. Please consider applying the attached one-line patch.

Once doing so, configuration of qtbase-opensource-src completes
successfully. The next failure is override_dh_auto_build-arch. There, we
run the just built qmake and that obviously fails with an Exec format
error. This is done to regenerate files that were included in the
source. There also is Lisandro's debian/generateTLDs.sh, which does more
of that. Can we use the build architecture qmake for these? Lisandro,
can you look into this part?

Helmut

--- qtbase-opensource-src-5.14.2+dfsg.orig/src/plugins/sqldrivers/configure.json
+++ qtbase-opensource-src-5.14.2+dfsg/src/plugins/sqldrivers/configure.json
@@ -67,6 +67,7 @@
             },
             "headers": "mysql.h",
             "sources": [
+                { "type": "pkgConfig", "args": "mysqlclient" },
                 { "type": "mysqlConfig", "query": "--libs_r", "cleanlibs": true },
                 { "type": "mysqlConfig", "query": "--libs", "cleanlibs": true },
                 { "type": "mysqlConfig", "query": "--libs_r", "cleanlibs": false },