As described in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=907539 , installing gimp-python solves the problem.
It looks like this can be fixed by adding a dependency from gimp-plugin- registry to gimp-python. ** Bug watch added: Debian Bug tracker #907539 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=907539 -- You received this bug notification because you are a member of Ubuntu Studio Bugs, which is subscribed to gimp-plugin-registry in Ubuntu. Matching subscriptions: Ubuntu Studio Bugs https://bugs.launchpad.net/bugs/1793270 Title: After upgrading to cosmic, GIMP python plugins no longer work Status in gimp-plugin-registry package in Ubuntu: New Status in gimp-plugin-registry package in Debian: New Bug description: When starting GIMP, messages similar to this are shown in the console: --- GIMP-Error: Unable to run plug-in "plugin-resynth-sharpen.py" (/usr/lib/gimp/2.0/plug-ins/plugin-resynth-sharpen.py) Failed to execute child process “python” (No such file or directory) --- This message is repeated for each python file in /usr/lib/gimp-2.0/plugins, and none of the plugins for which this error shows appear in the GIMP menus. The problem is fixed after installing gimp-python ProblemType: Bug DistroRelease: Ubuntu 18.10 Package: gimp-plugin-registry 9.20180625 ProcVersionSignature: Ubuntu 4.18.0-7.8-generic 4.18.5 Uname: Linux 4.18.0-7-generic x86_64 ApportVersion: 2.20.10-0ubuntu11 Architecture: amd64 CurrentDesktop: KDE Date: Wed Sep 19 11:19:45 2018 InstallationDate: Installed on 2017-08-17 (397 days ago) InstallationMedia: Kubuntu 17.10 "Artful Aardvark" - Alpha amd64 (20170725) SourcePackage: gimp-plugin-registry UpgradeStatus: Upgraded to cosmic on 2018-09-17 (1 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gimp-plugin-registry/+bug/1793270/+subscriptions -- Mailing list: https://launchpad.net/~ubuntustudio-bugs Post to : [email protected] Unsubscribe : https://launchpad.net/~ubuntustudio-bugs More help : https://help.launchpad.net/ListHelp

