[Rpm-ecosystem] RFC #417 %optional file attribute

[Neal Gompa]

On Mon, Mar 26, 2018 at 6:43 AM, Florian Festi <ffesti at redhat.com> wrote:
> Hi!
>
> We are currently pondering about #417 [1]. For adding a %optional file
> attribute that would allow adding file to to %files sections that may
> not be built under some circumstances (e.g. some architectures).
>
> It is already perfectly legal to have files not listed explicitly if
> they are within a directory that is included in the %file section. But
> some packages (examples wanted) may have trouble using this due to the
> way the package files are laid out.
>
> Otoh %optional would be another spec language key word that packagers
> have to deal with and we as RPM upstream developers have a hard time
> judging whether the benefit of the attribute really out weights the cost
> of bloating the spec language.
>
> Any input - especially with real world packages that would benefit such
> an addition - is welcome.
>

I personally wouldn't use %optional in most cases, just like I avoid
%missingok (the install-time counterpart to this).

That said, I think it's a perfectly valid strategy for dealing with
some types of content if you're trying to reduce/eliminate large
clusters of ugly conditionals in the %files section (or writing
scripts to generate files list manifests to pass to the files
section). While you can absolutely go without this feature, I think
that's more of a matter for distributions to consider. For example,
SUSE allows for empty file manifests in their packages, while Fedora
does not. And until a few months ago, rich dependencies were banned in
Fedora, while they've been allowed in SUSE for a while.

There are specs that do detection and analysis to fill in these
entries via the manifest, which I consider to be no worse than the
%optional tag for files section. This just reduces the need for
writing potentially error-prone extra scripts for this.

However, I'd like to see a warning thrown whenever a file listed as
%optional is not included because it's not there, just so that
information is captured and obvious when someone looks back through
build logs or something.


-- 
真実はいつも一つ！/ Always, there's only one truth!