Dependency package conflict with aur package

Not sure if i am plain stupid or pacman is… :smile: maybe someone can give me a hint:
I’m using the lcms2-ff-git aur package which provides lcms2 with fast float plugin. This results in a different licencing that is reflected by the aur package.

The package has the required provides and conflicts sections set so it should be detected as a drop-in replacement for lcms2 by pacman.

When i try to install e.g. vlc pacman fails with a package conflict:

$ trizen -S vlc
:: Pacman command: /usr/bin/sudo /usr/bin/pacman -S vlc
resolving dependencies...
looking for conflicting packages...
:: lcms2 and lcms2-ff-git are in conflict. Remove lcms2-ff-git? [y/N]

Why does pacman try to install lcms2 although a drop in replacement is already there? :grimacing:

Because libplacebo specifically requires I would guess that you AUR package isn’t at that version so pacman tries to install one that is.


What magic did you do to find this information? (I assume you did not read through all possible dependencies on your own?)

But i’m curious:
lcms2 does not provide a in that “version” - or i don’t know how to read that version information…

I used pactree -r lcms2 and then found the branch that led to vlc. There was only one package there, libplacebo. Then I used pacman -Si libplacebo to see what it required.

It is in the provides for the package:

Repository      : extra
Name            : lcms2
Version         : 2.14-2
Description     : Small-footprint color management engine, version 2
Architecture    : x86_64
URL             :
Licenses        : MIT
Groups          : None
Provides        :
Depends On      : libtiff
Optional Deps   : None
Conflicts With  : None
Replaces        : None
Download Size   : 214.36 KiB
Installed Size  : 674.96 KiB
Packager        : Felix Yan <>
Build Date      : Mon 02 Jan 2023 04:22:29 PM CST
Validated By    : MD5 Sum  SHA-256 Sum  Signature

hm…but this is not defined in the PKGBUILD for the official lcms2 package…is there some automagic happening somewhere?

When i explicitely add this to the AUR PKGBUILD it works as it should:
provides=('lcms2' '')


Yes. From the PGBUILD man page on provides:

If the provision name appears to be a library (ends with .so), makepkg will try to find the library in the built package and append the correct version. Appending the version yourself disables automatic detection.


I only had a look at the arch wiki - this specific section is missing there :frowning:

memo to self: use man more often… :smiley:


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