ROS2 galactic demo node can't start

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I have installed ROS2 Galactic by following the tutorial on a fresh Ubuntu 20.04. Unfortunately, I cannot run the very first demo node ros2 run demo_nodes_cpp talker. I get such an error:

error while loading shared libraries: libfmt.so.6: cannot open shared object file: No such file or directory

When I check if libfmt-dev is installed, I have it.

apt-cache policy libfmt-dev 
libfmt-dev:
  Installed: 6.1.2+ds-2
  Candidate: 6.1.2+ds-2
  Version table:
 *** 6.1.2+ds-2 500
        500 http://no.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
        100 /var/lib/dpkg/status

I don't understand what the issue is. When I try to debug as in here, I can get 'Hello World!'.

I also tried to install using debian packages as in this tutorial. I get a completely different error then:

source /opt/ros/galactic/setup.bash 
user:~$ ros2 run demo_nodes_cpp talker
terminate called after throwing an instance of 'rclcpp::exceptions::RCLError'
  what():  failed to initialize rcl init options: failed to load shared library 'librmw_cyclonedds_cpp.so' due to dlopen error: librmw_cyclonedds_cpp.so: cannot open shared object file: No such file or directory, at /tmp/binarydeb/ros-galactic-rcutils-4.0.2/src/shared_library.c:99, at /tmp/binarydeb/ros-galactic-rmw-implementation-2.4.1/src/functions.cpp:75, at /tmp/binarydeb/ros-galactic-rcl-3.1.2/src/rcl/init_options.c:75

And then the crash report pop-up occurs. Anyone has any ideas?

Thanks