We don't have access to RedHat iso files at the moment. Rasmus is looking into it.

Please inform what error you faced installing MariaDB from the yum repository. I want to track if its an RPM issue or a yum issue. Thanks

The error was a conflict between the MariaDB-server package and the mysql-libs package, which is installed by default. Here's a snippet of the error text:
...
file /usr/share/mysql/norwegian/errmsg.sys from install of mysql-libs-5.1.61-1.el6_2.1.x86_64 conflicts with file from package MariaDB-server-5.3.7-116.el5.i386
file /usr/share/mysql/polish/errmsg.sys from install of mysql-libs-5.1.61-1.el6_2.1.x86_64 conflicts with file from package MariaDB-server-5.3.7-116.el5.i386
file /usr/share/mysql/portuguese/errmsg.sys from install of mysql-libs-5.1.61-1.el6_2.1.x86_64 conflicts with file from package MariaDB-server-5.3.7-116.el5.i386
file /usr/share/mysql/romanian/errmsg.sys from install of mysql-libs-5.1.61-1.el6_2.1.x86_64 conflicts with file from package MariaDB-server-5.3.7-116.el5.i386
file /usr/share/mysql/russian/errmsg.sys from install of mysql-libs-5.1.61-1.el6_2.1.x86_64 conflicts with file from package MariaDB-server-5.3.7-116.el5.i386
file /usr/share/mysql/serbian/errmsg.sys from install of mysql-libs-5.1.61-1.el6_2.1.x86_64 conflicts with file from package MariaDB-server-5.3.7-116.el5.i386
file /usr/share/mysql/slovak/errmsg.sys from install of mysql-libs-5.1.61-1.el6_2.1.x86_64 conflicts with file from package MariaDB-server-5.3.7-116.el5.i386
...

I could install MariaDB only if I removed mysql-libs; and if I removed mysql-libs the cronie, cronie-anacron, crontabs.noarch, and postfix packages would also be removed because they depend on the mysql-libs package (and they can't be re-installed after installing MariaDB, because of the dependency on mysql-libs).

I believe we are Providing and Obsoleting mysql-libs (see MDEV-74 for more information and use serg's latest build)

Also, libaio – afaik our cmake removes that. libaio is only required for mysql, not for mariadb (last i checked)

Colin, I think libaio-devel on the build machines is a must. It is sadly not hard requirement for the build, but it is one of the big things in Innodb(and XtraDB) 5.5, so it must be in our packages for the best performance. Check Inaam's blog http://blogs.innodb.com/wp/2010/04/innodb-performance-aio-linux/

Thanks wlad.

Now, why do we disable it in cmake? Last time I looked at it, we did. I have no idea if this has changed recently.

Colin, we do not disable it in cmake. If libaio-dev (with headers and libraries) is on the box it will be used, if it is not on the box it won't.

If build runs with -DBUILD_CONFIG=mysql_release (which is used on Unixes for official release builds) missing libaio is normally not allowed, unless -DIGNORE_AIO_CHECK=1 is also given. Additionally, -DBUILD_CONFIG=mysql_release prefers to link with static libaio, to minimize runtime dependencies of the server.
This is a bit complicated logic (I'd rather made libaio-devel hard build dependency), but some people asked for graceful handling of missing libaio and other people were unhappy with libaio as additional runtime dependency, so it works this way now.

What is done on buildbot, I do not have a clear idea of. I do not exclude any possibility that -DIGNORE_AIO_CHECK was used temporarily because not every buildbot host had libaio-devel installed..

The CentOS 6 buildbot slaves are up and running. In order to create RHEL 6 buildbot slaves we need to renew our old, or purchase a new, RHEL subscription from Red Hat.