configure: libs.mysql is missing transitive deps

As a continuation of the supposedly fixed QTBUG-58536: 

Following the new configuration syntax, I am now trying to specify mysql lib via the following syntax:

-sql-mysql MYSQL_INCDIR=E:\msys64\mingw64\include\mariadb MYSQL_LIBDIR=E:\msys64\mingw64\lib MYSQL_LIBS="-l mysqlclient"

But I still get an error during configuration:

ERROR: Feature 'sql-mysql' was enabled, but the pre-condition 'libs.mysql' failed.

Note that prior to Qt 5.8 I was configuring via:

-L E:\msys64\mingw64\lib -qt-sql-mysql -l mysqlclient -I E:\msys64\mingw64\include\mariadb

And I was getting a working Qt build, with properly working mysql support, so the issue is not with the library but with the Qt configuration.

EDIT: In the config log I found a bunch of undefined references in libmysqlclient.a, so maybe the new build system fails to properly locate external dependencies to the library? I am attaching the log to the report.