[OE-core] Problems with rebuilds caused by sstate cache changes

[Otavio Salvador]

Hello,

I've been getting a fairly big number of build failures caused by ${S}
being reuse for rebuild. Those happen, most of time, when I sync our
repository with OE-Core and other layers.

The failures are caused by same source being reuse for two or more
builds, without PR bump. So patching fails, file rename fails, file
removal fails and so on.

For the Yocto upcoming release it might be a big problem since they're
using OEBasicHash by default but not being catch by this because their
autobuilders /remove/ their tmp dir from time to time. I don't!

I think Yocto ought to use rm_work by default for now to workaround
the issue. Thoughts?

-- 
Otavio Salvador                             O.S. Systems
E-mail: otavio at ossystems.com.br  http://www.ossystems.com.br
Mobile: +55 53 9981-7854              http://projetos.ossystems.com.br