Jtdylktuy

I'm trying to install GIMP with apt-get install on Ubuntu 18.04.1. It produces a dependency error:

$ sudo apt-get install gimp

Reading package lists... Done

Building dependency tree       

Reading state information... Done

Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming.

The following information may help to resolve the situation:



The following packages have unmet dependencies:

 gimp : Depends: libgegl-0.3-0 (>= 0.3.0) but it is not going to be installed

E: Unable to correct problems, you have held broken packages.

Following the chain of dependencies:

The following packages have unmet dependencies:

 libgegl-0.3-0 : Depends: libumfpack5 (>= 1:4.5.2) but it is not going to be installed

 libumfpack5 : Depends: libcholmod3 (>= 1:4.5.2) but it is not going to be installed

 libcholmod3 : Depends: liblapack3 but it is not going to be installed or liblapack.so.3

 liblapack3 : Depends: libgfortran4 (>= 7) but it is not going to be installed

 libgfortran4 : Depends: gcc-7-base (= 7.3.0-16ubuntu3) but 7.3.0-27ubuntu1~18.04 is to be installed

            Depends: libquadmath0 but it is not going to be installed

 libquadmath0 : Depends: gcc-8-base (= 8-20180414-1ubuntu2) but 8.2.0-1ubuntu2~18.04 is to be installed

E: Unable to correct problems, you have held broken packages.

The chain ends with gcc-7-base and gcc-8-base, both of which are already installed:

$ apt-cache policy gcc-8-base

gcc-8-base:

  Installed: 8.2.0-1ubuntu2~18.04

  Candidate: 8.2.0-1ubuntu2~18.04

  Version table:

 *** 8.2.0-1ubuntu2~18.04 100

        100 /var/lib/dpkg/status

     8-20180414-1ubuntu2 500

        500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages

$ apt-cache policy gcc-7-base

gcc-7-base:

  Installed: 7.3.0-27ubuntu1~18.04

  Candidate: 7.3.0-27ubuntu1~18.04

  Version table:

 *** 7.3.0-27ubuntu1~18.04 100

        100 /var/lib/dpkg/status

     7.3.0-16ubuntu3 500

        500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages

although under slightly different names that I can't decipher.

$ dpkg --get-selections | grep hold returns nothing, indicating that I have not, in fact, held any packages.

I've tried an update/upgrade/autoremove cycle. I've tried apt-get install -f. I've tried apt-get clean. None of these had any effect whatsoever.

I've installed Keybase and VS Code from PPAs. Other than that, this is a pretty fresh installation of 18.04, and I haven't done anything outside of the repos (or outside of apt-get install) except for those two things.

How do I figure out what the problem is, and how do I figure out how to fix it?

Edit: These repos are active in /etc/apt/sources.list:

deb http://us.archive.ubuntu.com/ubuntu/ bionic main restricted

deb http://us.archive.ubuntu.com/ubuntu/ bionic universe

deb http://us.archive.ubuntu.com/ubuntu/ bionic multiverse

deb [arch=amd64] https://packages.microsoft.com/repos/vscode stable main

and this in /etc/apt/sources.list.d/keybase.list:

deb http://prerelease.keybase.io/deb stable main

There are no others.