Centos – How RPM found conflict during installation

It helps to understand a little about how RPM works here.

RPM will be automatically adding requirements for particular classifications of file that it knows about (eg ELF shared libraries, #! scripts, etc):

http://www.rpm.org/max-rpm-snapshot/s1-rpm-depend-auto-depend.html

What is happening here is that some of the contents of the payload have been picked up with having requirements that are not packaged:

/home/rpmbuild/python/Python-2.6.4-root/usr/bin/python2.6
/usr/local/bin/python2.6

We can verify this by running rpmbuild -bi Python.spec to run the build up to the install stage. Based on the information supplied above you could search for files:

find /home/rpmbuild/python/Python-2.6.4-root/ -type f -exec grep \ /home/rpmbuild/python/Python-2.6.4-root/usr/bin/python2.6

I'd say you're looking at:

/home/rpmbuild/Python-2.6.4-root/usr/bin/python2.6-config for the the file that has a shebang that refers to the full buildroot and a bunch of scripts that refer to /usr/local/bin/python2.6

RPM isn't doing anything wrong here, and the details of the right way to fix this up will often be specific to the build of the package you're building.

One approach to fixing this would be to set AutoProvReq: no in the preamble of the SPEC file, eg directly after Group: Python. This should give you an installable RPM but you could argue that it's not taking full advantage of RPM's dependency model and you'd have incorrect paths in some of your Python package files.

Lets specifically look at the Python build and try and understand what we could do to fix this in a more comprehensive way.

Your %install section uses the macro %makeinstall which expands by default as:

[pnasrat@centos5 ~]$ rpm -E '%makeinstall'

  /usr/bin/make \
    prefix=/usr \
    exec_prefix=/usr \
    bindir=/usr/bin \
    sbindir=/usr/sbin \
    sysconfdir=/etc \
    datadir=/usr/share \
    includedir=/usr/include \
    libdir=/usr/lib64 \
    libexecdir=/usr/libexec \
    localstatedir=/var \
    sharedstatedir=/usr/com \
    mandir=/usr/share/man \
    infodir=/usr/share/info \
  install

For reference I tend to consult the upstream Fedora SPEC, which is much more complicated but can be made to build (with some modification and a patch for autotools versions IIRC) a parallel python26 package. I'm not going to go into the detail of that right now but if we look at how they install the key line is:

make install DESTDIR=%{buildroot}

I'd strongly recommend doing that rather than disabling AutoProvReq. As Python is a libtool based build that is probably better than the %makeinstall macro as you've already configured prefix. That seems to do the right thing by inspecting here. Note, if you are rebuilding with this change you'll also want to add:

%clean
rm -rf $RPM_BUILD_ROOT

And want a similar rm line at the beginning of the %install section. This all seems to work for me:

[pnasrat@centos5 RPMS]$ rpm --test -ivh x86_64/Python-2.6.4-1.x86_64.rpm 
Preparing...                ########################################### [100%]

It might well be worth using a python2.6 package provided elsewhere, I believe IUSCommunity provides packages, as documented here - http://agilesysadmin.net/recent-python-on-rhel-or-centos. These are probably much closer to the fedora packages.

The -1: token is the Epoch tag, so it looks like your RPM may have been built with an Epoch equaling 1. If that's the case, foo-lib-cpp-devel's dependency on foo must include the Epoch, like so:

Requires: foo = 1:0.7.0-1

Or, using macros:

Requires: foo = %{epoch}:%{version}-%{release}