[Fedora-packaging] disttag

[Michael Schwendt]

On Tue, 01 Mar 2005 07:41:08 -0600, Tom 'spot' Callaway wrote:

> Let me reiterate. I am fundamentally opposed to a disttag that can
> "expand to virtually everything". Hence, the macro definition of
> disttag, and the limitation of the defined possiblities.

Let me expand on my comment then.

We don't use the disttag for branding, do we? The purpose of appending a
disttag to the package release is not in flagging a package file as being
for a specific distribution environment. If you disagree, a tag like
"2.el4" is a very poor choice.

The purpose of a disttag postfix -- is it the primary or sole purpose? --
is in making it possible that a single src.rpm can be built for multiple
distribution releases without needing to worry about EVR comparison for
upgrade paths.

Using this disttag postfix is transparent to the packager, except for the
%{?disttag} macro that must be appended to the Release value. Whether the
postfix will be ".FC2", ".fc3", ".RHEL4" or empty should not be something
the package developer needs to worry about. Yes, the macro can be
undefined and then would expand to nothing and would append nothing. This
would be the case for every build machine which isn't updated to define
%disttag somewhere.

Hence I'd like to avoid a multi-purpose macro, which is not only used to
append a release postfix, but which is also relied on upon finding out the
build target distribution.

The earlier posted dist tag list 

  0.el2 0.rh7 0.rh8 0.rh9 1.el3 1.fc1 1.fc2 1.fc3 2.el4 2.fc4 2.fc5
  2.fc6 3.el5

is enough of a kludge already. An ugly kludge, which pretends an upgrade
path which is unsupported, and which makes package file names ugly too.
But it would achieve what it's supposed to achieve, provided that every
package update is built and released for all newer distro releases.

But please, if we go as far as defining a %disttag value somewhere in our
build environments, which is also to be used for determining the target
distro in conditional spec sections, better let's define a second macro. A
second macro, which has the sole purpose of making it unnecessary to
examine redhat-release in the spec file.

That one could be everything from a generic %distribution value to a
specific %{?fedora} and %{?rhel}, which expand to a numerical release
version. Would also allow much more obvious rpmbuild --define "fedora 4"
builds.  I'd rather check for "%{?rhel}" == "4" than to check for
"%{?disttag}" == ".2.el4".