I'm following https://www.mono-project.com/download/stable/#download-lin-ubuntu to install mono on ubuntu. However in the last step I get
sudo apt install mono-devel 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: mono-devel : Depends: libglib2.0-0 (>= 2.56.3) but 2.56.1-2ubuntu1 is to be installed Recommends: mono-csharp-shell but it is not going to be installed Recommends: referenceassemblies-pcl but it is not going to be installed Recommends: msbuild but it is not going to be installed E: Unable to correct problems, you have held broken packages.
My Ubuntu is indeed 18.04. What should I do?
sudo apt -f install; cat /etc/apt/sources.list.d/mono-official-stable.list [sudo] password for lz: Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: android-libadb android-libbase android-libcutils android-liblog android-sdk-platform-tools-common gcc-7-base:i386 libboost-random1.62.0 libboost-regex1.62.0 linux-headers-4.13.0-21 linux-headers-4.13.0-21-generic linux-headers-4.13.0-36 linux-headers-4.13.0-36-generic linux-image-4.13.0-21-generic linux-image-4.13.0-36-generic linux-image-extra-4.13.0-21-generic linux-image-extra-4.13.0-36-generic linux-signed-image-4.13.0-21-generic linux-signed-image-4.13.0-36-generic linux-signed-image-generic Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 69 not upgraded. deb https://download.mono-project.com/repo/ubuntu stable-bionic main