[root@chiba ~]# conary pin kernel:build-tree=2.6.19.4-0.1-1[kernel.smp] [root@chiba ~]# conary erase kernel:build-tree=2.6.19.4-0.1-1[kernel.smp] Not erasing kernel:build-tree - it is pinned.

To erase this kernel:build-tree, run:
conary unpin 'kernel:build-tree=/conary.rpath.com@rpl:devel//1/2.6.19.4-0.1-1[~!kernel.debug,~!kernel.debugdata,~!kernel.numa,~kernel.smp is: x86_64]'
conary erase 'kernel:build-tree=/conary.rpath.com@rpl:devel//1/2.6.19.4-0.1-1[~!kernel.debug,~!kernel.debugdata,~!kernel.numa,~kernel.smp is: x86_64]'

[root@chiba ~]# conary update 'kernel:build-tree=/conary.rpath.com@rpl:devel//1/2.6.17.11-1.1-1[~!kernel.debug,~!kernel.debugdata,~!kernel.numa,~kernel.smp]'
Applying update job:
    Update  kernel:build-tree (2.6.19.4-0.1-1[~!kernel.debug,~!kernel.debugdata,~!kernel.numa,~kernel.smp] -> 2.6.17.11-1.1-1[~!kernel.debug,~!kernel.debugdata,~!kernel.numa,~kernel.smp])
Creating rollback...