Cannot install libglib2.0-dev on ubuntu 20.04.1

[Addons Zz]

I already tried running `apt update/upgrade`, but it did not make any difference.

Why these versions conflicts are happening?

1. libglib2.0-bin : Conflicts: libglib2.0-bin:i386 but 2.64.2-1~fakesync1 is to be installed
1. libglib2.0-bin:i386 : Conflicts: libglib2.0-bin but 2.64.3-1~ubuntu20.04.1 is installed
1. libglib2.0-dev : Depends: libglib2.0-0 (= 2.64.2-1~fakesync1) but 2.64.3-1~ubuntu20.04.1 is installed
1. libglib2.0-0 : Breaks: libglib2.0-0:i386 (!= 2.64.3-1~ubuntu20.04.1) but 2.64.2-1~fakesync1 is to be installed
1. libglib2.0-0:i386 : Breaks: libglib2.0-0 (!= 2.64.2-1~fakesync1) but 2.64.3-1~ubuntu20.04.1 is installed

```
$ sudo aptitude install libglib2.0-dev
The following NEW packages will be installed:
  gcc-10-base:i386{a} libblkid-dev{a} libblkid1:i386{a} libc6:i386{a} libcrypt1:i386{a} libelf1:i386{a} libffi-dev{a} libffi7:i386{a} libgcc-s1:i386{a} libglib2.0-0:i386{ab}
  libglib2.0-bin:i386{ab} libglib2.0-dev{b} libglib2.0-dev-bin{a} libidn2-0:i386{a} libmount-dev{a} libmount1:i386{a} libpcre2-8-0:i386{a} libpcre2-dev{a} libpcre2-posix2{a}
  libpcre3:i386{a} libselinux1:i386{a} libselinux1-dev{a} libsepol1-dev{a} libunistring2:i386{a} zlib1g:i386{a}
0 packages upgraded, 25 newly installed, 0 to remove and 0 not upgraded.

Need to get 8.701 kB of archives. After unpacking 41,3 MB will be used.
The following packages have unmet dependencies:
 libglib2.0-bin : Conflicts: libglib2.0-bin:i386 but 2.64.2-1~fakesync1 is to be installed
 libglib2.0-bin:i386 : Conflicts: libglib2.0-bin but 2.64.3-1~ubuntu20.04.1 is installed
 libglib2.0-dev : Depends: libglib2.0-0 (= 2.64.2-1~fakesync1) but 2.64.3-1~ubuntu20.04.1 is installed
 libglib2.0-0 : Breaks: libglib2.0-0:i386 (!= 2.64.3-1~ubuntu20.04.1) but 2.64.2-1~fakesync1 is to be installed
 libglib2.0-0:i386 : Breaks: libglib2.0-0 (!= 2.64.2-1~fakesync1) but 2.64.3-1~ubuntu20.04.1 is installed
open: 2; closed: 4; defer: 0; conflict: 0

The following actions will resolve these dependencies:

     Keep the following packages at their current version:
1) libglib2.0-0:i386 [Not Installed]
2) libglib2.0-bin:i386 [Not Installed]
3) libglib2.0-dev [Not Installed]

Accept this solution? [Y/n/q/?] y
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.
```

```
$ cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.1 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.1 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal
```

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this issue and helping to make Ubuntu better. Examining the information you have given us, this does not appear to be a bug report so we are closing it and converting it to a question in the support tracker. We understand the difficulties you are facing, but it is better to raise problems you are having in the support tracker at https://answers.launchpad.net/ubuntu if you are uncertain if they are bugs. You can also find help with your problem in the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org. For help on reporting bugs, see https://help.ubuntu.com/community/ReportingBugs.

[Sebastien Bacher (seb128)]

> libglib2.0-dev : Depends: libglib2.0-0 (= 2.64.2-1~fakesync1) but 2.64.3-1~ubuntu20.04.1 is installed

it sounds like you installed libglib2.0-0 from focal-updates but don't have that source enabled anymore?

[Addons Zz (addonszz)]

I do not have installed libglib2.0-dev as you can see

```
$ dpkg -l | grep glib2.0
ii libglib2.0-0:amd64 2.64.3-1~ubuntu20.04.1 amd64 GLib library of C routines
ii libglib2.0-bin 2.64.3-1~ubuntu20.04.1 amd64 Programs for the GLib library
ii libglib2.0-data 2.64.3-1~ubuntu20.04.1 all Common files for GLib library
```

I did not changed my source repositories. Do I need to change something on it?

This is my sources.list:
```
$ cat /etc/apt/sources.list
# deb cdrom:[Ubuntu 20.04.1 LTS _Focal Fossa_ - Release amd64 (20200731)]/ focal main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://br.archive.ubuntu.com/ubuntu/ focal main restricted
deb-src http://br.archive.ubuntu.com/ubuntu/ focal main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb-src http://br.archive.ubuntu.com/ubuntu/ focal-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://br.archive.ubuntu.com/ubuntu/ focal universe
# deb-src http://br.archive.ubuntu.com/ubuntu/ focal universe
# deb-src http://br.archive.ubuntu.com/ubuntu/ focal-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://br.archive.ubuntu.com/ubuntu/ focal multiverse
# deb-src http://br.archive.ubuntu.com/ubuntu/ focal multiverse
# deb-src http://br.archive.ubuntu.com/ubuntu/ focal-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb-src http://br.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu focal partner
# deb-src http://archive.canonical.com/ubuntu focal partner

deb http://security.ubuntu.com/ubuntu focal-security restricted main
# deb-src http://security.ubuntu.com/ubuntu focal-security main restricted
deb http://security.ubuntu.com/ubuntu focal-security universe
# deb-src http://security.ubuntu.com/ubuntu focal-security universe
deb http://security.ubuntu.com/ubuntu focal-security multiverse
# deb-src http://security.ubuntu.com/ubuntu focal-security multiverse

# This ...

[Sebastien Bacher (seb128)]

> I did not changed my source repositories. Do I need to change something on it?

well you did at some point,

 ii libglib2.0-0:amd64 2.64.3-1~ubuntu20.04.1 amd64 GLib library of C routines

that version isn't available in your sources, it comes from focal-updates, so either you enabled the updates repository to install it or did something else?

the issue is that libglib2.0-dev need to be a matching version but you removed the source containing the version of glib you are based on, you either need to enable focal-updates or reinstall the focal version of libglib2.0-0 (apt install --reinstall libglib2.0-0/focal)

[Addons Zz (addonszz)]

Thanks! Soon after installing Ubuntu, I had disabled the updates (by setting it to use only security updates, see attachment picture).

I did not know that changing that would change my system sources.

I changed it back to `All updates` and now I was able to install `libglib2.0-dev`
```
$ sudo apt-get install nemo
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  cinnamon-desktop-data cinnamon-l10n fonts-lato gist hwdata javascript-common libcinnamon-desktop4 libgail-3-0 libjs-jquery libnemo-extension1 libruby2.7 libxapp1 nemo-data
  nemo-fileroller rake ruby ruby-json ruby-minitest ruby-net-telnet ruby-power-assert ruby-test-unit ruby-xmlrpc ruby2.7 rubygems-integration xapps-common
Suggested packages:
  apache2 | lighttpd | httpd ri ruby-dev bundler
The following NEW packages will be installed:
  cinnamon-desktop-data cinnamon-l10n fonts-lato gist hwdata javascript-common libcinnamon-desktop4 libgail-3-0 libjs-jquery libnemo-extension1 libruby2.7 libxapp1 nemo nemo-data
  nemo-fileroller rake ruby ruby-json ruby-minitest ruby-net-telnet ruby-power-assert ruby-test-unit ruby-xmlrpc ruby2.7 rubygems-integration xapps-common
0 upgraded, 26 newly installed, 0 to remove and 118 not upgraded.
Need to get 11,3 MB of archives.
After this operation, 61,0 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://br.archive.ubuntu.com/ubuntu focal/main amd64 fonts-lato all 2.0-2 [2.698 kB]
...
```

First I had tried to downgrade it, but it was about to uninstall everything on my computer:
```
$ sudo add-apt-repository universe
'universe' distribution component is already enabled for all sources.

$ sudo add-apt-repository multiverse
'multiverse' distribution component is already enabled for all sources.

$ sudo add-apt-repository restricted
'restricted' distribution component is already enabled for all sources.

$ sudo apt install --reinstall libglib2.0-0/focal
Reading package lists... Done
Building dependency tree
Reading state information... Done
Selected version '2.64.2-1~fakesync1' (Ubuntu:20.04/focal [amd64]) for 'libglib2.0-0'
The following packages were automatically installed and are no longer required:
  accountsservice-ubuntu-schemas apturl-common fprintd gir1.2-accountsservice-1.0 gir1.2-gck-1 gir1.2-gcr-3 gir1.2-gdesktopenums-3.0 gir1.2-gdm-1.0 gir1.2-geoclue-2.0
  gir1.2-gnomebluetooth-1.0 gir1.2-gnomedesktop-3.0 gir1.2-goa-1.0 gir1.2-graphene-1.0 gir1.2-gweather-3.0 gir1.2-json-1.0 gir1.2-mutter-6 gir1.2-nm-1.0 gir1.2-nma-1.0 gir1.2-rsvg-2.0
  gir1.2-upowerglib-1.0 gjs gnome-screensaver gnome-session-bin gnome-session-common gnome-shell-common gnome-startup-applications indicator-applet indicator-appmenu indicator-bluetooth
  indicator-datetime indicator-keyboard indicator-messages indicator-power indicator-printers indicator-session indicator-sound jayatana libbamf3-2 libcue2 libfcitx-config4
  libfcitx-gclient1 libfcitx-utils0 libfprint-2-2 libgjs0g libgnome-autoar-0-0 libgnome-panel0 libgsf-1-114 libgsf-1-common libido3-0.1-0 liblightdm-gobject-1-0 libmozjs-68-0
  libpam-fprintd libtracker-control-...

[Sebastien Bacher (seb128)]

Great that it worked out. The downgrade was trying to remove things because libglib binaries need to be on the same version so it was necessary to downgrade libglib2.0-bin/focal in addition to the main library