yum install and weird architecture behaviour

I was just trying to accomplish what you would think was a relatively easy task – installing the PHP-GD package from the Atomic Rocket Turtle repository for 64bit CentOS 5 and ran into a slightly cryptic problem.

Running yum install php-gd simply produced a dependancy error

php-gd-5.2.13-1.el5.art.i386 from atomic has depsolving problems
–> Missing Dependency: libt1.so.5 is needed by package php-gd-5.2.13-1.el5.art.i386 (atomic)
Error: Missing Dependency: libt1.so.5 is needed by package php-gd-5.2.13-1.el5.art.i386 (atomic)
You could try using –skip-broken to work around the problem
You could try running: package-cleanup –problems
package-cleanup –dupes
rpm -Va –nofiles –nodigest
The program package-cleanup is found in the yum-utils package.

A quick check that I’m using an up to date mirror along with a yum clean all to make sure nothing weird is happening leaves me back where I started, but a bit of digging later reveals that this is an interesting problem with yum on 64bit systems where it is trying to install the 32bit package and looking for 32bit dependancies. Forcing the install to be 64bit with yum install php-gd.x86_64 works first time 🙂