fontconfig: migrate to util-linux-libuuid

[ericLemanissier]

To avoid conflict with system libuuid

Specify library name and version: fontconfig/*

see #17664 and #17427 (comment) for motivation and rationale

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• I've read the contributing guidelines.
• I've used a recent Conan client version close to the currently deployed.
• I've tried at least one configuration locally with the conan-center hook activated.

[ericLemanissier]

blocks:

• [tk] Migrate tk to conan 2.0 #17427
• libxft: conan v2 support #17485

[jcar87]

Hi @ericLemanissier - thanks for your contribution. On the surface of this, this makes sense. However, would you able to provide more details (preferably in the PR description) about how these potential conflicts manifest when consuming this recipe? Thanks!

[ericLemanissier]

@jcar87 see #17664 and #17427 (comment)

[prince-chrismc]

@ericLemanissier @jwillikers @samuel-emrys We are going to be rolling this back since it's causing lots of issues with the graph conflicts

[ericLemanissier]

Why not moving forward, instead of backwards?

[prince-chrismc]

It's easier to fix one then try to track down all the other recipes and get PRs through on a Friday :)
Now we know there's a problem we can plan how to get through it.

Hopefully that's a reasonable response :)

[samuel-emrys]

If this is being rolled back, what's the way forward on system package conflicts? Ie xorg/system which brings in the util-linux-libuuid variant and conflicts with libuuid

[prince-chrismc]

@samuel-emrys I do not see that searching the repo https://github.com/search?q=repo%3Aconan-io%2Fconan-center-index+util-linux-libuuid&type=code so I am not sure where that is being pulled in 🤔 If you can give me more imformation I'd appreciate that 🙏

We have only 16 recipes using the libuuid
https://github.com/search?q=repo%3Aconan-io%2Fconan-center-index%20requires%20libuuid&type=code from a basic search and I think we can make a simple plan to introduce all those changes "at once" but what see

[samuel-emrys]

@prince-chrismc see #17427 (comment) for context. fontconfig is where libuuid is being pulled into the tree

[samuel-emrys]

#17664 is where util-linux-libuuid was added. All packages currently using libuuid should migrate to util-linux-libuuid and libuuid should be deprecated

[ericLemanissier]

I don't think we can migrate the 16 recipes "at once" because there are dependencies between these 16 packages, but it is true that we should all be ready to approve quickly the 16 PRs when the migration is started, to minimize the disruption (hoping that github or C3I don't let us down during the process)

The conflict Sam is talking about is one that cannot be detected by conan, because it is a conflict between a system package and a conan package.

[prince-chrismc]

All packages currently using libuuid should migrate to util-linux-libuuid and libuuid should be deprecated

Can we (i.e the Conan team) plan this next week so we cause users the least amount of disruption? Does that make sense?
I know historically it was one at a time by the community, but for cases like this, the reinvigorate team wants to find a better solution 🤞

The issue is it's late at night and most have logged off so we decided to save the work for next week, a few more days will not delay other efforts -- it's bad timing for a human perspective

The conflict Sam is talking about is one that cannot be detected by conan, because it is a conflict between a system package and a conan package.

Could the xorg/system package also list the requirement on util-linux-libuuid or a provides so that an error get's flagged? (thinking out loud) how do we as maintainers document that in the code?

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There's no objection to this change getting rolled out but we just want to do it correctly. :)

[samuel-emrys]

Can we (i.e the Conan team) plan this next week so we cause users the least amount of disruption? Does that make sense?

Yep this sounds reasonable to me.

Could the xorg/system package also list the requirement on util-linux-libuuid or a provides so that an error get's flagged? (thinking out loud) how do we as maintainers document that in the code?

Yeah this isn't a bad idea. xorg wouldn't use it obviously, because it's a system package, but that would at least cause a conflict if libuuid exists elsewhere in the dep tree. This would have to be applied to any other system packages on CCI as well, if they have the dependency.