проблемы при обновлении с 18 LTS до 20 LTS. обновления вроде бы установились. что делать?

Я пытаюсь обновить ubuntu 18 до 20 LTS. извините за то, что был таким нубом. Я следую этому руководству: [https://askubuntu.com/questions/1231570/cant-upgrade-ubuntu-18-04-to-20-04-because-of-please-install-all -available-upd] [1] , но я получаю сообщение об ошибке, что мне сначала нужно обновить кое-что. вывод терминала находится ниже.

Я понимаю, что «3 пакета можно обновить». как я могу их обновить. Если я запускаю "sudo apt dist-upgrade", я получаю:

" Чтение списков пакетов ... Готово Построение дерева зависимостей
Чтение информации о состоянии .. . Готово Расчет обновления ... Готово 0 обновлено, 0 установлено заново, 0 удалено и 0 не обновлено. "

после при запуске:" sudo do- release-upgrade " Проверка наличия нового выпуска Ubuntu Перед обновлением установите все доступные обновления для вашего выпуска. что происходит? могу ли я обновить 3 пакета?

вот полный вывод терминала:

pernille@pernille-ThinkPad-T60:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.5 LTS
Release:    18.04
Codename:   bionic
pernille@pernille-ThinkPad-T60:~$ ^C
pernille@pernille-ThinkPad-T60:~$ sudo apt install update-manager-core
[sudo] password for pernille: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
update-manager-core is already the newest version (1:18.04.11.13).
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
pernille@pernille-ThinkPad-T60:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
pernille@pernille-ThinkPad-T60:~$ sudo apt list --upgradable
Listing... Done
r-cran-boot/bionic,bionic 1.3-20-1.1 all [upgradable from: 1.3-20-1xenial0]
r-cran-codetools/bionic,bionic 0.2-15-1.1 all [upgradable from: 0.2-15-1cran1xenial0]
r-cran-spatial/bionic 7.3-11-2build1 amd64 [upgradable from: 7.3-11-1xenial0]
pernille@pernille-ThinkPad-T60:~$ sudo apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
pernille@pernille-ThinkPad-T60:~$ sudo apt --purge autoremove
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
pernille@pernille-ThinkPad-T60:~$ sudo apt install update-manager-core
Reading package lists... Done
Building dependency tree       
Reading state information... Done
update-manager-core is already the newest version (1:18.04.11.13).
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
pernille@pernille-ThinkPad-T60:~$ 
pernille@pernille-ThinkPad-T60:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
pernille@pernille-ThinkPad-T60:~$ sudo apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
pernille@pernille-ThinkPad-T60:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
pernille@pernille-ThinkPad-T60:~$ ^C
pernille@pernille-ThinkPad-T60:~$ sudo apt upgrade
[sudo] password for pernille: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
pernille@pernille-ThinkPad-T60:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
pernille@pernille-ThinkPad-T60:~$ sudo apt dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
pernille@pernille-ThinkPad-T60:~$ sudo do-release-upgrade -d -f DistUpgradeViewGtk3
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
pernille@pernille-ThinkPad-T60:~$ sudo apt update
Hit:1 http://dk.archive.ubuntu.com/ubuntu bionic InRelease
Get:2 http://dk.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]   
Get:3 http://dk.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB] 
Get:4 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]    
Get:5 https://esm.ubuntu.com/infra/ubuntu bionic-infra-security InRelease [7,458 B]
Get:6 http://dk.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages [2,100 kB]
Get:7 https://esm.ubuntu.com/infra/ubuntu bionic-infra-updates InRelease [7,457 B]
Get:8 http://security.ubuntu.com/ubuntu bionic-security/main amd64 DEP-11 Metadata [48.6 kB]
Get:9 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 DEP-11 Metadata [60.4 kB]
Get:10 http://security.ubuntu.com/ubuntu bionic-security/multiverse amd64 DEP-11 Metadata [2,464 B]
Get:11 http://dk.archive.ubuntu.com/ubuntu bionic-updates/main i386 Packages [1,298 kB]
Get:12 http://dk.archive.ubuntu.com/ubuntu bionic-updates/main amd64 DEP-11 Metadata [294 kB]
Get:13 http://dk.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 Packages [1,736 kB]
Get:14 http://dk.archive.ubuntu.com/ubuntu bionic-updates/universe i386 Packages [1,567 kB]
Get:15 http://dk.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 DEP-11 Metadata [290 kB]
Get:16 http://dk.archive.ubuntu.com/ubuntu bionic-updates/multiverse amd64 DEP-11 Metadata [2,464 B]
Get:17 http://dk.archive.ubuntu.com/ubuntu bionic-backports/universe amd64 DEP-11 Metadata [9,288 B]
Fetched 7,675 kB in 4s (1,953 kB/s)                                   
Reading package lists... Done
Building dependency tree       
Reading state information... Done
3 packages can be upgraded. Run 'apt list --upgradable' to see them.
pernille@pernille-ThinkPad-T60:~$ apt list --upgradable
Listing... Done
r-cran-boot/bionic,bionic 1.3-20-1.1 all [upgradable from: 1.3-20-1xenial0]
r-cran-codetools/bionic,bionic 0.2-15-1.1 all [upgradable from: 0.2-15-1cran1xenial0]
r-cran-spatial/bionic 7.3-11-2build1 amd64 [upgradable from: 7.3-11-1xenial0]
pernille@pernille-ThinkPad-T60:~$ 
pernille@pernille-ThinkPad-T60:~$ sudo apt dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
pernille@pernille-ThinkPad-T60:~$ 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
pernille@pernille-ThinkPad-T60:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.