[CentOS-devel] still trying to build upstream srpms

Jeff Johnson n3npq at mac.com
Mon Sep 1 21:09:21 UTC 2008


On Sep 1, 2008, at 4:58 PM, Joe Pruett wrote:

>>> What's implied when people say mock is being used, is that there  
>>> are no special '--define', etc. flags passed to rpmbuild from  
>>> within mock.
>>
>> Hmmm, and why is passing --define (or not) relevant to anything in  
>> the real world?
>>
>> Yes, the CentOS issue is trying to identify a "reproducible  
>> build", as defined by the
>> RHEL build system, and rpm macros are often different and  
>> continuously changing.
>>
>> If the macros used were the only part of the "reproducible build"  
>> problem,
>> then --macrosused (and the RPMTAG_BUILDMACROS header extension)
>> solves the problem by spewing the list of all macros used
>> by rpmbuild (or any other rpm command) at termination,
>> and/or by including the equivalent list of used macros (and  
>> definitions) within a *.src.rpm
>> header.
>>
>> But the real problem is that all build systems contain versions of  
>> compilers and toolchains
>> that are different. That's a whole different class of problem.
>>
>> So not passing --define is hardly relevant imho, the tool chains  
>> used for building
>> are what is very tricky to identify and attempt to "reproduce".
>
> a lot of rpms use --define to control how the package is built,  
> what functions to enable in the package.  postgresql is a good  
> example.  it has 47 %if clauses in the spec file that directly or  
> indirectly rely on --define switches at rpmbuild time.
>
> this --macrosused/RPMTAG_BUILDMACROS sounds like exactly what i'm  
> looking for, but it doesn't appear to be part of the rpm system  
> used by rh/centos.
>

Yup. too bad for you & Centos.

FWIW, adding %dump at the very end of spec file, and grep'ping out
the used macros which are marked in the %dump spewage (unused
macros look like "^-14:..." while used macros look like ("-14=..." iirc)
will work with all versions of rpm I've ever touched.

FYI, the "-14" is "the level of macro recursion", and negative  
numbers are
global. The value identifies where the macro was defined. Not useful  
at all,
but that's what the "-14" is and does.

Porting --macrosused to rpm-4.5.6.7.8.9. ain't rocket science either ...

> but without the newer rpm system, how do the centos builders know  
> what flags to use to build an rpm?  are they all built without any  
> --define flags?  do we know that is how rh does it?

I'd guess that all the --with/--without "stuff" is hard wired into a
macro config file (or perhaps done directly by mock), another reason
why "No --define in mock ..." Simply Does Not Matter.

73 de Jeff


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