How to fix Fedora CoreOS rpm-ostree error: Transaction in progress: deploy --lock-finalization revision=... --disallow-downgrade

Problem:

When trying to install a package using rpm-ostree, you see an error message like

error: Transaction in progress: deploy --lock-finalization revision=5040eaabed46962a07b1e918ba5afa1502e1f898bf958673519cd83e986c228f --disallow-downgrade 

Solution

The error message means that currently there’s an rpm-ostree operating in progress and you need to wait for it to finish.

In order to see which process is running, use

ps aux | grep rpm

Example output:

[root@CoreOS uli]# ps aux | grep rpm
root         730 41.2  1.7 1218036 34568 ?       Ssl  18:41   0:30 /usr/bin/rpm-ostree start-daemon
zincati     1896  0.0  0.8 481172 17324 ?        Sl   18:41   0:00 rpm-ostree deploy --lock-finalization revision=5040eaabed46962a07b1e918ba5afa1502e1f898bf958673519cd83e986c228f --disallow-downgrade
root        3223  0.0  0.0 221452   832 pts/0    S+   18:42   0:00 grep --color=auto rpm

As you can see in the second line:

zincati 1896 0.0 0.8 481172 17324 ? Sl 18:41 0:00 rpm-ostree deploy --lock-finalization revision=5040eaabed46962a07b1e918ba5afa1502e1f898bf958673519cd83e986c228f --disallow-downgrade

the user zincati is currently running rpm-ostree on my system. zincati is the Fedora CoreOS auto-updater - in other words, an automatic system update is currently running on CoreOS.

In case the process got stuck and waiting doesn’t help reboot the system. Killing the process won’t work.