Answer by apaderno for "The following packages have been kept back:" Why and how do I solve it?

In my case, I got the message because I run sudo apt upgrade without first running sudo apt update.

$ sudo apt upgradeReading package lists... DoneBuilding dependency tree... DoneReading state information... DoneCalculating upgrade... DoneThe following packages have been kept back:  alsa-ucm-conf fonts-opensymbol libreoffice-base-core libreoffice-calc libreoffice-common libreoffice-core libreoffice-draw  libreoffice-gnome libreoffice-gtk3 libreoffice-help-common libreoffice-help-en-gb libreoffice-help-en-us libreoffice-impress  libreoffice-l10n-en-gb libreoffice-l10n-en-za libreoffice-math libreoffice-style-colibre libreoffice-style-elementary  libreoffice-style-yaru libreoffice-uiconfig-calc libreoffice-uiconfig-common libreoffice-uiconfig-draw  libreoffice-uiconfig-impress libreoffice-uiconfig-math libreoffice-uiconfig-writer libreoffice-writer libuno-cppu3  libuno-cppuhelpergcc3-3 libuno-purpenvhelpergcc3-3 libuno-sal3 libuno-salhelpergcc3-3 python3-uno uno-libs-private ure0 upgraded, 0 newly installed, 0 to remove and 34 not upgraded.

Running sudo apt-get --with-new-pkgs upgrade alsa-ucm-conf fonts-opensymbol libreoffice-base-core libreoffice-calc libreoffice-common libreoffice-core libreoffice-drawlibreoffice-gnome libreoffice-gtk3 libreoffice-help-common libreoffice-help-en-gb libreoffice-help-en-us libreoffice-impresslibreoffice-l10n-en-gb libreoffice-l10n-en-za libreoffice-math libreoffice-style-colibre libreoffice-style-elementarylibreoffice-style-yaru libreoffice-uiconfig-calc libreoffice-uiconfig-common libreoffice-uiconfig-drawlibreoffice-uiconfig-impress libreoffice-uiconfig-math libreoffice-uiconfig-writer libreoffice-writer libuno-cppu3libuno-cppuhelpergcc3-3 libuno-purpenvhelpergcc3-3 libuno-sal3 libuno-salhelpergcc3-3 python3-uno uno-libs-private ure as suggested in other answers did not help.

$ sudo apt-get --with-new-pkgs upgrade alsa-ucm-conf fonts-opensymbol libreoffice-base-core libreoffice-calc libreoffice-common libreoffice-core libreoffice-drawlibreoffice-gnome libreoffice-gtk3 libreoffice-help-common libreoffice-help-en-gb libreoffice-help-en-us libreoffice-impresslibreoffice-l10n-en-gb libreoffice-l10n-en-za libreoffice-math libreoffice-style-colibre libreoffice-style-elementarylibreoffice-style-yaru libreoffice-uiconfig-calc libreoffice-uiconfig-common libreoffice-uiconfig-drawlibreoffice-uiconfig-impress libreoffice-uiconfig-math libreoffice-uiconfig-writer libreoffice-writer libuno-cppu3libuno-cppuhelpergcc3-3 libuno-purpenvhelpergcc3-3 libuno-sal3 libuno-salhelpergcc3-3 python3-uno uno-libs-private ureReading package lists... DoneBuilding dependency tree... DoneReading state information... DoneE: Unable to locate package libreoffice-drawlibreoffice-gnomeE: Unable to locate package libreoffice-impresslibreoffice-l10n-en-gbE: Unable to locate package libreoffice-style-elementarylibreoffice-style-yaruE: Unable to locate package libreoffice-uiconfig-drawlibreoffice-uiconfig-impressE: Unable to locate package libuno-cppu3libuno-cppuhelpergcc3-3

I ran sudo apt update before sudo apt upgrade and it worked out.

$ sudo apt updateHit:1 https://dl.winehq.org/wine-builds/ubuntu mantic InReleaseHit:2 http://it.archive.ubuntu.com/ubuntu mantic InRelease                                                                      Get:3 http://it.archive.ubuntu.com/ubuntu mantic-updates InRelease [109 kB]                                                     Hit:4 http://security.ubuntu.com/ubuntu mantic-security InReleaseHit:5 http://it.archive.ubuntu.com/ubuntu mantic-backports InReleaseGet:6 http://it.archive.ubuntu.com/ubuntu mantic-updates/main amd64 Packages [331 kB]Get:7 http://it.archive.ubuntu.com/ubuntu mantic-updates/main i386 Packages [168 kB]Get:8 http://it.archive.ubuntu.com/ubuntu mantic-updates/universe amd64 Packages [296 kB]Get:9 http://it.archive.ubuntu.com/ubuntu mantic-updates/universe i386 Packages [123 kB]Fetched 1,027 kB in 1s (792 kB/s)                       Reading package lists... DoneBuilding dependency tree... DoneReading state information... Done34 packages can be upgraded. Run 'apt list --upgradable' to see them.