obs-ptz .deb package requires unavailable dependencies

[pmichaud]

When I try to install the obs-ptz 0.18.1 debian package on my Kubuntu 25.04 system, I get the following errors:

$ sudo dpkg -i ./obs-ptz-0.18.1-x86_64-linux-gnu.deb 
Selecting previously unselected package obs-ptz.
(Reading database ... 383881 files and directories currently installed.)
Preparing to unpack .../obs-ptz-0.18.1-x86_64-linux-gnu.deb ...
Unpacking obs-ptz (0.18.1) ...
dpkg: dependency problems prevent configuration of obs-ptz:
 obs-ptz depends on libqt6gui6t64 (>= 6.1.2); however:
  Package libqt6gui6t64 is not installed.
 obs-ptz depends on libqt6network6t64 (>= 6.4.0); however:
  Package libqt6network6t64 is not installed.
 obs-ptz depends on libqt6widgets6t64 (>= 6.3.0); however:
  Package libqt6widgets6t64 is not installed.
 obs-ptz depends on libqt6xml6t64 (>= 6.1.2); however:
  Package libqt6xml6t64 is not installed.

dpkg: error processing package obs-ptz (--install):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 obs-ptz
pmichaud@kiwi:/peach/share/systems/linux/obs-studio$ sudo apt install libqt6gui6t64
Package libqt6gui6t64 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
  libqt6gui6


Error: Package 'libqt6gui6t64' has no installation candidate
$

This seems to indicate that the correct Ubuntu package would be "libqt6gui6" instead of "libqt6gui6t64" (which seems to come from the debian backports repository). There also appears to be a libqt6gui6 package in Debian sid already.

Pm

[JackmTaco]

Same issue as well running on Debian 13.1

The following packages have unmet dependencies:
obs-ptz: Depends: libqt6gui6t64 (>= 6.1.2) but it is not installable
Depends: libqt6network6t64 (>= 6.4.0) but it is not installable
Depends: libqt6widgets6t64 (>= 6.3.0) but it is not installable
Depends: libqt6xml6t64 (>= 6.1.2) but it is not installable

[mmicmanagement]

Same problem here:

The following packages have unmet dependencies:
obs-ptz : Depends: libqt6core6t64 (>= 6.4.0) but it is not installable
Depends: libqt6gui6t64 (>= 6.1.2) but it is not installable
Depends: libqt6network6t64 (>= 6.4.0) but it is not installable
Depends: libqt6widgets6t64 (>= 6.3.0) but it is not installable
Depends: libqt6xml6t64 (>= 6.1.2) but it is not installable
E: Unable to correct problems, you have held broken packages.

[EdueskaWeiz]

The t64 suffix pins this down. Those package names come from the Debian/Ubuntu 64-bit time_t transition: Ubuntu 24.04 renamed the Qt6 runtime packages to libqt6gui6t64, libqt6core6t64 and so on. Ubuntu 25.04 and Debian 13 do not use those names — there the packages are plain libqt6gui6 etc., which is exactly what @pmichaud's apt output says.

Where it comes from in this repo: cmake/linux/defaults.cmake sets

set(CPACK_DEBIAN_PACKAGE_SHLIBDEPS ON)

so dpkg-shlibdeps derives the Depends: field from whatever packages own the linked libraries on the build machine. The CI builds on ubuntu-24.04 (.github/workflows/build-project.yaml), so the generated dependencies are the t64 names, and the resulting .deb is installable only on 24.04 and 24.10. Every other distro sees unsatisfiable dependencies — which matches all three reports here: Kubuntu 25.04, Debian 13.1, and the same on a fifth package for @mmicmanagement.

So this is not a wrong or missing dependency, it is a package built for one specific distro release being published as a generic .deb.

Options, roughly in order of effort:

1. Declare the Qt dependencies explicitly with alternatives instead of letting shlibdeps guess, e.g. libqt6gui6 | libqt6gui6t64. Debian's | syntax covers both naming schemes with one package.
2. Build one .deb per supported distro release in CI and name the artifacts accordingly, so it is obvious which one belongs to which release.
3. Treat the .deb as Ubuntu-24.04-only and point everyone else at the .tar.xz from the same release, which has no dependency metadata at all.

Workaround in the meantime: use the .tar.xz artifact from the release instead of the .deb and unpack it into your OBS plugin directory. The libraries themselves are present on your system under their non-t64 names — it is only the dependency metadata that does not match.

Worth noting for anyone landing here from #331: this is independent of the OBS 32.2.1 loading problem. Fixing one does not fix the other.

[EdueskaWeiz]

Correction to my comment above — the workaround I suggested does not work, sorry.

I wrote that you could use the .tar.xz from the release instead of the .deb. Checking the v0.18.2 assets afterwards: the only .tar.xz there is obs-ptz-0.18.2-source.tar.xz, which is the source tarball, not a binary package. Unpacking it into a plugin directory does nothing useful. There is no binary tarball for Linux — the release ships only the .deb and the -dbgsym.ddeb.

What actually works, since the libraries themselves are present and only the dependency names do not match:

sudo dpkg -i --force-depends ./obs-ptz-0.18.2-x86_64-linux-gnu.deb

That is a blunt instrument — it installs despite the unmet dependencies — but here the unmet entries are the t64-renamed Qt6 packages whose non-t64 equivalents you already have, so the plugin finds its libraries at runtime. Check OBS's log afterwards to confirm the module loads.

If you would rather not force anything, extracting by hand avoids touching the package database:

dpkg-deb -x ./obs-ptz-0.18.2-x86_64-linux-gnu.deb /tmp/obs-ptz

and copy the plugin and data files from there into your OBS plugin directory.

The analysis in my previous comment stands — the dependency names are a dpkg-shlibdeps result baked in from the Ubuntu 24.04 build host. Only the suggested workaround was wrong.