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> Carla 2.0 RC3 is here!
On 2019-01-15 by falkTX

Hello everyone, happy new year!
This is a quick fix for the Carla Plugin Host (soon-to-be) stable series.
Only very small fixes here, and a change on how specific plugins load.
This release starts a "release early, release often" attitude, that hopefully I can maintain from now on.


  • Fix bridge-lv2-x11 crash when manually started from CLI
  • LV2: Don't prefer plugin bridges for certain hardcoded plugins (Calf, ir.lv2 and v1 series)
  • VST: Do not call plugin effEditIdle on update display opcode, fixing crashes for a few plugins

Previously a few plugins were hardcoded to run as plugin bridges, as they were deemed unsafe because of how they use their plugin UIs (instance-access).
Carla automatically started these plugins as bridges, as to not crash the main process when Gtk and Qt gets in the way.
Plugin state in bridges have a few issues (as plugin bridges are experimental right now), which I was hoping to fix before the final 2.0 is here.
But that will not happen it seems (not an easy fix), so now these plugins will run normally as all others do, in the same process.
This means the following possible breaking changes:

  • If v1 plugin series are compiled with a Qt version different than the one Carla is using, expect a crash on load or soon afterwards
  • Calf plugin UIs will be missing their graphs by default, unless you disable running plugin UIs in bridge mode in Carla settings

This is not an issue for other plugin UIs that use Qt or Gtk, as they do not use LV2 instance-access.
Carla runs Gtk and Qt LV2 UIs in a separate process, but because these UIs require direct access to the plugin instance, they cannot be bridged.


To download Carla binaries or source code, jump on over to the KXStudio downloads section.
If you're using the KXStudio repositories, you can simply install "carla-git" (plus "carla-lv2" and "carla-vst" if you're so inclined).
Bug reports and feature requests are welcome! Jump on over to the Carla's Github project page for those.


A "2.0-final" milestone is on GitHub, which lists the remaining issues to be fixed before 2.0 is considered "final".
New features already made its way to Carla, but sit on the develop branch.
When the "final" version is released, expect a 2.1-beta to come shortly afterwards.