Re: [Qemu-devel] [PATCH] docker: add installation to build tests

[Paolo Bonzini <pbonzini@redhat.com>]

----- Original Message -----
> From: "Fam Zheng" <famz@redhat.com>
> To: "Paolo Bonzini" <pbonzini@redhat.com>
> Cc: "alex bennee" <alex.bennee@linaro.org>, qemu-devel@nongnu.org
> Sent: Sunday, September 24, 2017 4:54:39 AM
> Subject: Re: [Qemu-devel] [PATCH] docker: add installation to build tests
> 
> On Fri, 09/22 17:52, Paolo Bonzini wrote:
> > On 22/09/2017 14:47, Fam Zheng wrote:
> > > On Fri, 09/22 13:42, Paolo Bonzini wrote:
> > >> Drop ccache on Fedora, because it fails on RHEL 7.4, it is not used
> > >> by any other distro and it is not particularly useful on throwaway
> > >> containers.
> > > 
> > > I wonder what exactly failed with ccache? Patchew relies on it to speed
> > > up
> > > compiling every series on the list. The ccache db is not throwaway with
> > > that in
> > > mind - git grep for CCACHE_DIR.
> > 
> > Got it.  For some reason the ccache dir in ~/.cache was owned by root.
> > I zapped it and now it works, so I've sent v2.
> 
> Hmm, right, root in the container can mess with it if you have NOUSER=1, we
> should avoid that.

Aha, so the brokenness happened when RHEL introduced user namespaces and the
container stopped running as root.  Then the persistent part of the
container's filesystem (the ccache dir) couldn't be accessed anymore from
within the user namespace.

Paolo