Can't Refresh Plugins in Carla

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G M Slater
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Can't Refresh Plugins in Carla

Post by G M Slater »

I am running Carla version 2.4.2 in Ubuntu Studio 22.04. When I click the Refresh button on the Add Plugins window (so I can scan for new plugins) nothing happens. The log is showing the following:

======= Starting engine =======
======= Engine started ========
Carla engine started, details:
Driver name: JACK
Sample rate: 48000
Process mode: Multi client
Traceback (most recent call last):
File "/usr/share/carla/carla_database.py", line 1692, in slot_refreshPlugins
if PluginRefreshW(self, self.host, self.fUseSystemIcons, self.hasLoadedLv2Plugins).exec_():
File "/usr/share/carla/carla_database.py", line 1230, in __init__
self.fThread.pluginLook.connect(self.slot_handlePluginLook)
TypeError: decorated slot has no signature compatible with SearchPluginsThread.pluginLook[float, str]

I have tried uninstalling/reinstalling Carla, but it did not resolve. Does anyone know what I need to do to get it working properly again?
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Largos
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Re: Can't Refresh Plugins in Carla

Post by Largos »

This is a bug with the version of Carla (2.4.2) that is shipped with ubuntu 22.04. The way I fixed it was to install the 2.4.3 from the kxstudio website.

https://launchpad.net/~kxstudio-debian/ ... o1_all.deb

https://launchpad.net/~kxstudio-debian/ ... _amd64.deb

IIRC you need to install them in that order because the first link is a dependency of the second.

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sudo apt install ./carla-data_2.4.3-1kxstudio1_all.deb
in the folder you downloaded will work.

You can usually get the links from here: https://kx.studio/Repositories:Applications but currently the link for the first deb file is broken but for future reference and future versions go to this link. Also if you want the wine bridges.
G M Slater
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Re: Can't Refresh Plugins in Carla

Post by G M Slater »

Largos - That worked perfectly. Thank you for the quick resolution!
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RyanH
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Re: Can't Refresh Plugins in Carla

Post by RyanH »

Thanks so much for this. I had been waiting slightly impatiently for Ubuntu Studio to come out with a fix in the next point release. Now I am a very happy man. :D

A note for anyone who might find themselves unable to install these with apt: I used dpkg and then it worked fine. Apt gave me sass about that dependency, even though I had already installed it.

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sunrat
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Re: Can't Refresh Plugins in Carla

Post by sunrat »

I think apt can use wildcards. From a directory with only those carla .debs:

Code: Select all

apt install ./*.deb

should work.

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cleary
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Re: Can't Refresh Plugins in Carla

Post by cleary »

Just thought I'd post a more supportable/correct resolution here - newer versions of carla are available in the backports repositories for ubuntu 22.04

you can verify this with:

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$ apt-cache policy carla
carla:
  Installed: 2.4.2-0ubuntu2
  Candidate: 2.4.2-0ubuntu2
  Version table:
     2.5.4-0ubuntu2~bpo22.04.1 100
        100 http://au.archive.ubuntu.com/ubuntu jammy-backports/universe amd64 Packages
 *** 2.4.2-0ubuntu2 500
        500 http://au.archive.ubuntu.com/ubuntu jammy/universe amd64 Packages
        100 /var/lib/dpkg/status

Which clearly shows the newer version available (if it doesn't, jump to the bottom of the page), but is not a "candidate" for installation - why?

The number (500) next to the universe version is higher than the number next to the backports version (100) - which is a process of prioritisation by apt called "pinning"

You can explicitly specify the version you want to install, but that's a short-term fix only. You want to change the pin priority for carla to get it from the backports repo, and to continue to prioritise that source into the future (in case updates get pushed in)

To change the pin priority, edit a new file:

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sudo nano /etc/apt/preferences.d/carla-backports

add the following contents:

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Package: carla*
Pin: release a=jammy-backports
Pin-Priority: 500

Then check apt-cache policy again

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$ apt-cache policy carla
carla:
  Installed: 2.4.2-0ubuntu2
  Candidate: 2.5.4-0ubuntu2~bpo22.04.1
  Version table:
     2.5.4-0ubuntu2~bpo22.04.1 500
        100 http://au.archive.ubuntu.com/ubuntu jammy-backports/universe amd64 Packages
 *** 2.4.2-0ubuntu2 500
        500 http://au.archive.ubuntu.com/ubuntu jammy/universe amd64 Packages
        100 /var/lib/dpkg/status

The backport version is now the candidate - you can install all the specific packages you need, or (more easily) do an upgrade:

Code: Select all

sudo apt-get upgrade

and you should see all the newer backport versions coming in (now, and into the future) :D

Troubleshooting:
If the backports are not available, put this into /etc/apt/sources.list.d/jammy-backports.list:

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deb http://au.archive.ubuntu.com/ubuntu/ jammy-backports main restricted universe multiverse
deb-src http://au.archive.ubuntu.com/ubuntu/ jammy-backports main restricted universe multiverse

then:

Code: Select all

sudo apt-get update
Last edited by cleary on Thu May 11, 2023 12:10 am, edited 4 times in total.
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sunrat
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Re: Can't Refresh Plugins in Carla

Post by sunrat »

@cleary that will certainly work to pin carla from backports, but it happens sometimes that the version from main will be updated to a higher version than backports. Such a situation happens currently for the nvidia-driver package in Debian Stable:

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$ apt list -a nvidia-driver
nvidia-driver/stable,now 470.182.03-1 amd64 [installed]
nvidia-driver/bullseye-backports 470.103.01-1~bpo11+1 amd64

Backports version will not build on 6.x kernels, whereas the main version does.

I prefer to keep backports at lower priority and only manually install backports version if there are issues with main version.

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cleary
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Re: Can't Refresh Plugins in Carla

Post by cleary »

@sunrat yes of course - note that I've only pinned the carla packages for the backports, so it won't affect any other packages.

Also note that I've pinned it at the same level as universe, therefore if a newer version (than backports) lands in there, it will still be installed as expected

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