Contexto: Eu tentei uma atualização de 14.04 LTS para 16.04 LTS, e tudo correu bem até o fim quando recebi uma mensagem dizendo que, embora a atualização tenha sido instalada, alguns erros ocorreram. Fazendo um pouco de escavação, parecia que o pacote 'ubuntu-desktop' tinha algumas dependências insolúveis. Saída de /var/log/dist-upgrade/apt.log:
Log time: 2017-01-09 10:30:59.192116
Starting pkgProblemResolver with broken count: 1
Starting 2 pkgProblemResolver with broken count: 1
Investigating (0) qtdeclarative5-ubuntu-ui-toolkit-plugin [ amd64 ] < none -> 1.3.1918+16.04.20160404-0ubuntu1 > ( libs )
Broken qtdeclarative5-ubuntu-ui-toolkit-plugin:amd64 Depends on qml-module-ubuntu-components [ amd64 ] < none -> 1.3.1918+16.04.20160404-0ubuntu1 > ( libs )
Considering qml-module-ubuntu-components:amd64 1 as a solution to qtdeclarative5-ubuntu-ui-toolkit-plugin:amd64 0
Holding Back qtdeclarative5-ubuntu-ui-toolkit-plugin:amd64 rather than change qml-module-ubuntu-components:amd64
Investigating (0) checkbox-converged [ amd64 ] < none -> 1.2.4-0ubuntu1 > ( oldlibs )
Broken checkbox-converged:amd64 Depends on qtdeclarative5-ubuntu-ui-toolkit-plugin [ amd64 ] < none -> 1.3.1918+16.04.20160404-0ubuntu1 > ( libs )
Considering qtdeclarative5-ubuntu-ui-toolkit-plugin:amd64 0 as a solution to checkbox-converged:amd64 -1
Holding Back checkbox-converged:amd64 rather than change qtdeclarative5-ubuntu-ui-toolkit-plugin:amd64
Investigating (1) checkbox-gui [ amd64 ] < none -> 1.2.4-0ubuntu1 > ( utils )
Broken checkbox-gui:amd64 Depends on checkbox-converged [ amd64 ] < none -> 1.2.4-0ubuntu1 > ( oldlibs )
Considering checkbox-converged:amd64 -1 as a solution to checkbox-gui:amd64 0
Holding Back checkbox-gui:amd64 rather than change checkbox-converged:amd64
Investigating (1) ubuntu-desktop [ amd64 ] < 1.361 > ( metapackages )
Broken ubuntu-desktop:amd64 Depends on checkbox-gui [ amd64 ] < none -> 1.2.4-0ubuntu1 > ( utils )
Considering checkbox-gui:amd64 0 as a solution to ubuntu-desktop:amd64 0
Removing ubuntu-desktop:amd64 rather than change checkbox-gui:amd64
Done
Starting pkgProblemResolver with broken count: 1
Starting 2 pkgProblemResolver with broken count: 1
Investigating (0) ubuntu-desktop [ amd64 ] < 1.361 > ( metapackages )
Broken ubuntu-desktop:amd64 Depends on checkbox-gui [ amd64 ] < none -> 1.2.4-0ubuntu1 > ( utils )
Considering checkbox-gui:amd64 1 as a solution to ubuntu-desktop:amd64 10000
Reinst Failed early because of qtdeclarative-abi-5-5-0:amd64
Reinst Failed because of libubuntugestures5:amd64
Reinst Failed because of qml-module-ubuntu-components:amd64
Reinst Failed because of qtdeclarative5-ubuntu-ui-toolkit-plugin:amd64
Reinst Failed because of checkbox-converged:amd64
Done
ERROR:root:failed to mark 'ubuntu-desktop' for install (E:Unable to correct problems, you have held broken packages.)
No entanto, meu sistema parecia estar indo bem em 16.04, então ignorei isso por um tempo. Mas recentemente, meu laptop tem sido um pouco buggy (fontes do sistema não são exibidas após a reativação e a incapacidade de desligar corretamente depois disso), então eu acho que é melhor eu tentar instalar o 'ubuntu-desktop'. Eu fiz algumas das minhas próprias tentativas usando synaptic e aptitude da linha de comando (em vez do apt-get) para ver se a sua resolução de dependência inteligente poderia ajudar, mas sem sucesso. A saída de sudo aptitude install ubuntu-desktop é muito semelhante ao apt.log acima [ edit : incluída integralmente mediante solicitação nos comentários, e eu também incluí o resultado após rejeitar a primeira sugestão de resolução de dependência]
$ sudo aptitude install ubuntu-desktop
The following NEW packages will be installed:
checkbox-converged{a} checkbox-gui{a} libandroid-properties1{a} libhardware2{a} libhybris{a} libhybris-common1{a} libmedia1{a} liboxideqt-qmlplugin{a} liboxideqtcore0{ab} liboxideqtquick0{a}
libqt5organizer5{ab} libqt5quicktest5{a} libubuntugestures5{ab} libubuntutoolkit5{ab} libunity-webapps0{a} pyotherside{a} python3-aptdaemon.pkcompat{ab} qml-module-io-thp-pyotherside{a}
qml-module-qt-labs-folderlistmodel{a} qml-module-qt-labs-settings{a} qml-module-qtgraphicaleffects{a} qml-module-qtquick-layouts{a} qml-module-qttest{a} qml-module-ubuntu-components{ab}
qml-module-ubuntu-layouts{ab} qml-module-ubuntu-performancemetrics{a} qml-module-ubuntu-test{ab} qml-module-ubuntu-web{a} qmlscene{a} qtdeclarative5-dev-tools{a} qtdeclarative5-test-plugin{a}
qtdeclarative5-ubuntu-ui-toolkit-plugin{a} suru-icon-theme{a} ubuntu-desktop ubuntu-mobile-icons{a} unity-webapps-common{a} unity-webapps-qml{a} unity-webapps-service{a} webapp-container{ab}
webbrowser-app{ab}
0 packages upgraded, 40 newly installed, 0 to remove and 63 not upgraded.
Need to get 43.8 MB/44.2 MB of archives. After unpacking 161 MB will be used.
The following packages have unmet dependencies:
qml-module-ubuntu-test : Depends: qtbase-abi-5-5-1 which is a virtual package, provided by:
- libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed. - libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed.
liboxideqtcore0 : Depends: qtbase-abi-5-5-1 which is a virtual package, provided by:
- libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed. - libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed.
libqt5organizer5 : Depends: qtbase-abi-5-5-1 which is a virtual package, provided by:
- libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed. - libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed.
webapp-container : Depends: qtbase-abi-5-5-1 which is a virtual package, provided by:
- libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed. - libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed.
Depends: qtdeclarative-abi-5-5-0 which is a virtual package, provided by:
- libqt5qml5, but 5.6.1-4ubuntu1~xenialoverlay1~4 is installed.
qml-module-ubuntu-layouts : Depends: qtdeclarative-abi-5-5-0 which is a virtual package, provided by:
- libqt5qml5, but 5.6.1-4ubuntu1~xenialoverlay1~4 is installed.
python3-aptdaemon.pkcompat : Depends: python3-aptdaemon (= 1.1.1+bzr982-0ubuntu14) but 1.1.1+bzr982-0ubuntu16~ubuntu16.04~ppa1 is installed.
Conflicts: packagekit but 1.1.1-1ubuntu1~ubuntu16.04~ppa1 is installed.
Conflicts: packagekit:i386 but it is not going to be installed.
qml-module-ubuntu-components : Depends: qtbase-abi-5-5-1 which is a virtual package, provided by:
- libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed. - libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed.
Depends: qtdeclarative-abi-5-5-0 which is a virtual package, provided by:
- libqt5qml5, but 5.6.1-4ubuntu1~xenialoverlay1~4 is installed.
libubuntutoolkit5 : Depends: qtbase-abi-5-5-1 which is a virtual package, provided by:
- libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed. - libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed.
aptdaemon : Breaks: python3-aptdaemon.pkcompat but 1.1.1+bzr982-0ubuntu14 is to be installed.
webbrowser-app : Depends: qtbase-abi-5-5-1 which is a virtual package, provided by:
- libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed. - libqt5core5a, but 5.6.1+dfsg-3ubuntu1~xenialoverlay1~4+fix1 is installed.
Depends: qtdeclarative-abi-5-5-0 which is a virtual package, provided by:
- libqt5qml5, but 5.6.1-4ubuntu1~xenialoverlay1~4 is installed.
libubuntugestures5 : Depends: qtdeclarative-abi-5-5-0 which is a virtual package, provided by:
- libqt5qml5, but 5.6.1-4ubuntu1~xenialoverlay1~4 is installed.
Internal error: found 2 (choice -> promotion) mappings for a single choice.
Internal error: found 2 (choice -> promotion) mappings for a single choice.
The following actions will resolve these dependencies:
Keep the following packages at their current version:
1) checkbox-converged [Not Installed]
2) checkbox-gui [Not Installed]
3) liboxideqt-qmlplugin [Not Installed]
4) liboxideqtcore0 [Not Installed]
5) liboxideqtquick0 [Not Installed]
6) libqt5organizer5 [Not Installed]
7) libubuntugestures5 [Not Installed]
8) libubuntutoolkit5 [Not Installed]
9) libunity-webapps0 [Not Installed]
10) python3-aptdaemon.pkcompat [Not Installed]
11) qml-module-ubuntu-components [Not Installed]
12) qml-module-ubuntu-layouts [Not Installed]
13) qml-module-ubuntu-test [Not Installed]
14) qml-module-ubuntu-web [Not Installed]
15) qtdeclarative5-ubuntu-ui-toolkit-plugin [Not Installed]
16) ubuntu-desktop [Not Installed]
17) unity-webapps-common [Not Installed]
18) unity-webapps-qml [Not Installed]
19) unity-webapps-service [Not Installed]
20) webapp-container [Not Installed]
21) webbrowser-app [Not Installed]
Accept this solution? [Y/n/q/?] n
The following actions will resolve these dependencies:
Install the following packages:
1) liboxideqtcore0 [1.13.6-0ubuntu1 (xenial)]
Keep the following packages at their current version:
2) checkbox-converged [Not Installed]
3) checkbox-gui [Not Installed]
4) liboxideqt-qmlplugin [Not Installed]
5) liboxideqtquick0 [Not Installed]
6) libqt5organizer5 [Not Installed]
7) libubuntugestures5 [Not Installed]
8) libubuntutoolkit5 [Not Installed]
9) libunity-webapps0 [Not Installed]
10) python3-aptdaemon.pkcompat [Not Installed]
11) qml-module-ubuntu-components [Not Installed]
12) qml-module-ubuntu-layouts [Not Installed]
13) qml-module-ubuntu-test [Not Installed]
14) qml-module-ubuntu-web [Not Installed]
15) qtdeclarative5-ubuntu-ui-toolkit-plugin [Not Installed]
16) ubuntu-desktop [Not Installed]
17) unity-webapps-common [Not Installed]
18) unity-webapps-qml [Not Installed]
19) unity-webapps-service [Not Installed]
20) webapp-container [Not Installed]
21) webbrowser-app [Not Installed]
Downgrade the following packages:
22) oxideqt-codecs-extra [1.19.4-0ubuntu0.16.04.1 (now, xenial-security, xenial-updates) -> 1.13.6-0ubuntu1 (xenial)]
Accept this solution? [Y/n/q/?] n
Acho que isso pode estar relacionado à questão da barra de lançamento aqui link que inevitavelmente aponta alguns conflitos entre qtbase-abi-5-5-1 e qtbase-abi-5-6-1, mas eu não tenho o conhecimento para determinar de forma conclusiva isso. Dada a minha saída, certamente parece que algo está acontecendo com minhas bibliotecas do Qt (com as quais eu não mexo).
Para completar:
$ lsb_release -crid
Distributor ID: Ubuntu
Description: Ubuntu 16.04.1 LTS
Release: 16.04
Codename: xenial