Re: 32-rc1: "CROSS_COMPILE changed" message breaks compilation

From: Sam Ravnborg
Date: Sun Oct 11 2009 - 17:29:16 EST


On Mon, Sep 28, 2009 at 09:25:36PM +0200, Pavel Machek wrote:
> Hi!
>
> > > After update to 2.6.32-rc1, I'm getting
> > >
> > > "Makefile:197: *** CROSS_COMPILE changed from "ccache" to to "ccache ". Use "make mrproper" to fix it up. Stop.
> > >
> > > Note that the message has typo in it ("to to")... What is worse, the
> > > message triggers even when I try to run make mrproper. Ouch.
> >
> > The massage is changed in kbuild-fixes.git - but it addresses only ARCH=
> >
> > As a followup to your other mails:
> > The reason to use "make mrproper" is that when ARCH or CROSS_COMPILE changes
> > you have generally either decided to build for a new architecture or
> > you have changed the way you build the kernel (new toolchain or whatever).
> > So to clean up using "make mrproper" is perfectly justified.
> >
> > The target group that uses CROSS_COMPILE to enable ccache are using
> > CROSS_COMPILE is a way it is not designed for so they should expect that it
> > is not a perfect match.
>
> What is the recommended way to run ccache, then?
ccache is a frontend to gcc - so I would have expected
you would use:

make CC="ccache gcc"

Or does ccache also benefit ld and as and the other that receive
the $(CROSS_COMPILE) prefix?

Sam
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