dpkg-fsys-usrunmess - Man Page

undoes the merged-/usr-via-aliased-dirs mess


dpkg-fsys-usrunmess [option...]


dpkg-fsys-usrunmess is a tool to fix up filesystems that have been installed anew with recent installers with unfortunate defaults or migrated to the broken merged /usr via aliased directories layout, which is not supported by dpkg. See the dpkg FAQ.

The program will perform the following overall actions:

Note: When running the program from some shells such as bash(1) or zsh(1), after executing it, you might need to request the shell to forget all remembered executable locations with for example hash -r.

Note: Some directories might linger after the migration in case they contain untracked files. A list is printed once the script has finished for further investigation.

Warning: Note that this operation has the potential to render the system unusable or broken in case of a sudden crash or reboot, unexpected state of the system, or possible bugs in the script. Be prepared with recovery media and consider doing backups beforehand.


-p,  --prompt

Prompt at the time of no return, so that the debug output or the shadow hierarchy can be evaluated before proceeding.


Enables or disables generating and installing a regression prevention package into the system. If no option has been specified, the action to take will be prompted.

The generated package contains the Protected field set to yes to protect against accidental removal of the package.

-n,  --no-act

This option enables the dry-run mode, where no destructive action takes place, only the preparatory part.

-?,  --help

Show the usage message and exit.


Show the version and exit.



This setting defines whether to enable dry-run mode.

See Also



2022-07-01 1.21.9 dpkg suite