Re: xen-unstable: build fails

[Juergen Gross <juergen.gross@ts.fujitsu.com>]

On 03/17/11 09:11, Keir Fraser wrote:
> On 17/03/2011 05:52, "Juergen Gross"<juergen.gross@ts.fujitsu.com>  wrote:
>
>> The reason is clear: XEN_ROOT is set to a *relative* path. And when make is
>> including a Makefile, it switches the working directory to the directory of
>> the included Makefile. Including another Makefile via XEN_ROOT then is the
>> problem...
>
> Well it's not clear to me. In my tests, including another Makefile does not
> change the working directory, only recursive make with -C specified does
> that. That seems logical -- pulling in standard rules containing wildcard
> globs would otherwise have unpredictable results, if the wildcards were
> evaluated in the directory of the included Makefile.
>
> In your case, if Config.mk was getting run with incorrect relative XEN_ROOT,
> how would the earlier include lines in that file work? You are getting an
> error on '-include $(XEN_ROOT)/.config', but there are earlier (and
> unconditional!) include lines in Config.mk that also reference XEN_ROOT. I
> suppose they must be working.
>
> So I think something is weird in your environment, or your make is broken.
> However in this one specific failure case I can avoid redefining XEN_ROOT
> outside xen/Makefile, since all hypervisor builds start at that Makefile. So
> you can see whether c/s 23048 in xen-unstable staging fixes your build. I
> applied it as it happens to be a teeny tiny cleanup as well.

We are both right :-)

I created /.config with:

$(warning /.config: $(MAKEFILE_LIST))

and got the following with "make tools":

make -C tools install
make[1]: Entering directory `/root/xen-unstable.hg/tools'
make[2]: Entering directory `/root/xen-unstable.hg/tools'
make -C check install
make[3]: Entering directory `/root/xen-unstable.hg/tools/check'
../../.config:1: /.config:  Makefile ../../tools/Rules.mk ../../Config.mk 
../../config/Linux.mk ../../config/StdGNU.mk ../../config/x86_64.mk 
/usr/include/../../.config


So the problem is not changing the working directory, but implicit directory
search. $(XEN_ROOT)/.config expands as ../../.config and this file was not
found, so make searches in /usr/include, as the file path is relative. And
/usr/include/../../.config results as /.config :-(

The problem is still the relative XEN_ROOT specification.
Or the missing .config under XEN_ROOT, so creating this file solves my
problem. :-)


Juergen

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Juergen Gross                 Principal Developer Operating Systems
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