Fedora 22: 'dnf update' UnicodeDecodeError

With the change from Fedora 21 to 22 the package manager yum has been deprecated and replaced by dnf.

Upgrading to Fedora 22, many users report an UnicodeDecodeError on dnf execution. At this point, it is no more possible to install the necessary packages (python-dnf-plugins-extra) for troubleshooting, because the requested 'dnf install python-dnf-plugins-extras' results in the same Error.

In this situation, the use of the deprecated yum (on Fedora systems /usr/bin/yum-depricated) is recommended. Following these steps, the problem will be solved:

1. step - installation of the necessary packages:
  su -c '/usr/bin/yum-depricated install python-dnf-plugins-extras'

2. step - yum2dnf migration:
  su -c 'dnf migrate all'

After the successful migration, all dnf commands will work as expected!