Re: [OE-core] [PATCH v5 07/15] kernel-yocto.bbclass: Disable ccache when rust-kernel is enabled

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Wed, 2026-02-04 at 13:31 +0100, Yoann Congal wrote:
> On Wed Feb 4, 2026 at 1:05 PM CET, Paul Barker wrote:
> > On Thu, 2026-01-29 at 08:39 -0800, Sadineni, Harish via
> > lists.openembedded.org wrote:
> > > From: Yoann Congal <yoann.congal@smile.fr>
> > > 
> > > Currently, a ccache enabled build fails with:
> > >   |   HOSTRUSTC scripts/generate_rust_target
> > >   |   HOSTCC  scripts/kallsyms
> > >   |   HOSTCC  scripts/sorttable
> > >   |   HOSTCC  scripts/asn1_compiler
> > >   |   TOUCH   include/generated/gcc-plugins.h
> > >   |   DESCEND objtool
> > >   | error: multiple input filenames provided (first two filenames are gcc and
> > > .../tmp/work-shared/qemux86-64/kernel-source/scripts/generate_rust_target.rs)
> > > 
> > > when using ccache, value of "HOSTCC=cache gcc" when this value is passing
> > > to rustc, It is thinking gcc is a input file. when ccache is not used "HOSTCC=gcc" is passed.
> > > 
> > > Disable ccache for kernel build if rust-kernel is enabled to workaround
> > > this.
> > > 
> > > Signed-off-by: El Mehdi YOUNES <elmehdi.younes@smile.fr>
> > > Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
> > > Signed-off-by: Harish Sadineni <Harish.Sadineni@windriver.com>
> > 
> > This patch is good, but we should try to get the issue resolved upstream
> > if we can so that ccache can be used.
> > 
> > Has this been reported upstream yet? Could you also open a bug in our
> > bugzilla to track this?
> 
> Hello,
> 
> For context, a lengthy discussion happened on this patch here:
> https://lore.kernel.org/openembedded-core/CA+TGqK9Yd2WWKrhMkhofF-8N0cESCSefWD2DXr4sBO9fDQXyrg@mail.gmail.com/t/#u
> 
> And, sadly, we lack resources at the moment on our side to follow-up on this :-/

Putting some links alongside this to more details would probably at
least help a bit, particularly if ccache upstream documents it is
imcompatible with rust...

Cheers,

Richard