[Fedora-packaging] arched BuildRequires?

[Panu Matilainen]

On 06/13/2013 09:30 PM, Michael Schwendt wrote:
> On Thu, 13 Jun 2013 19:09:29 +0200, Mattias Ellert wrote:
>
>> tor 2013-06-13 klockan 17:34 +0200 skrev Simone Caronni:
>>
>>>
>>> Exactly, here an example of a Koji build done with _isa'ed
>>> BuildRequires (taken from the link I've posted before):
>>>
>>> $ rpm -qpR libguac-client-vnc-0.6.0-4.fc17.src.rpm
>>> cairo-devel(x86-64)
>>> gnutls-devel(x86-64)
>>> libguac-devel(x86-64) = 0.6.0
>>> libvncserver-devel(x86-64)
>>> rpmlib(FileDigests) <= 4.6.0-1
>>> rpmlib(CompressedFileNames) <= 3.0.4-1
>>>
>>> This means I can't rebuild the src.rpm on an i686. This is wrong.
>>
>> If what you say above was true it would be a problem. But it doesn't
>> work like that.
>
> True, it doesn't really work like that, but %_isa in BuildRequires
> adds a confusing problem nevertheless.
>
> BuildRequires in the spec file become the src.rpm's Requires.
> If those Requires are arch-specific, you cannot use tools like
> yum-builddep or "rpm" to query the package's build requirements.
> You would need to reconstruct the src.rpm always for the target
> arch (not only if there are arch-conditional BuildRequires).
>
> The src.rpm is built on an arbitrary build host, and Fedora publishes
> a single src.rpm build in the sources repo. It's just lame if the user
> of an x86_64 installation downloads src.rpm packages, which contain
> x86-32, ppc or other arch-specific dependencies. That doesn't add any
> value at all.
>
>> $ rpmbuild --rebuild globus-common-14.9-3.fc18.src.rpm
>
> That doesn't evaluate the src.rpm's Requires as yum-builddep or "rpm -qpR" do.
> So, why obfuscate the BuildRequires and the src.rpm's Requires?

No, rpmbuild does not use src.rpm requires for determining 
build-requires because they're no good for that. The requires of src.rpm 
only reflect what build-requires were active during the creation of that 
specific src.rpm file, not what its build-requires for some other build 
on other arch, different --with/--without switches etc might be.

>
>> ... build succeeds ... because the BRs needed on the build system's architecture are there
>>
>
> Nasty, isn't it? The package specifies '(x86-32)' requirements, but you've
> just built for '(x86-64)'.
>

See above, you're misunderstanding the meaning of src.rpm requires.

	- Panu -