[juju 2.7.6] juju broken actions

Versions:
$ juju version 2.7.6-bionic-amd64

With new juju 2.7.6 stable actions stopped working for multiple charms.

Example:
$ juju run -u graylog/0 show-admin-password
/tmp/juju-exec266017833/script.sh: line 1: show-admin-password: command not found

$ juju actions ceph-osd
Action Description
...
list-disks \
    List disks.
    Documentation: https://jujucharms.com/ceph-osd/

$ juju run -u ceph-osd/0 list-disks
/tmp/juju-exec971452262/script.sh: line 1: list-disks: command not found

This output does not depend on charm version. Actions worked ok with this environment before.