[pacman-dev] Orphaning files in the filesystem after unsuccessful pacman -R

[Nagy Gabor]

> Hello,
> 
> It seems I found a bug in pacman. Some information first:
>   version: pacman 4.1.2-5 prebuilt from official repo
>    system: Linux 3.12.7-2-ARCH i686
> 
> So it happened when I tried to remove alex package.
> 
> $ sudo pacman -R alex
>     [sudo] password for michael:
>     checking dependencies...
> 
>     Packages (1): alex-3.1.3-1
> 
>     Total Removed Size:   1.18 MiB
> 
>     :: Do you want to remove these packages? [Y/n] y
>     error: cannot remove file '/usr/': Read-only file system
>     ldconfig: Can't create temporary cache file /etc/ld.so.cache~:
> Read-only file system
>     error: command failed to execute correctly
> 
> Uhm... I forgot I have root filesystem mounted read-only. No problem.
> 
> $ sudo mount / -o remount,rw
> $ sudo pacman -R alex
>     error: target not found: alex
> 
> What? How could pacman remove the package from a read-only filesystem?

Well, pacman just removed the database entry (from the
writeable /var/lib/pacman/)...
This behaviour is clearly odd here, but it is not easy to say what is
the expected behaviour in general, for example, what should we do when
only ONE file cannot be removed? AFAIK, pacman cannot "undo"
transaction after it has been started atm (transaction rollback is not
implemented), so the only options are "pre-remove check" or stop.

Theoretically, pacman should collect "file foo has become untracked due
to a removal error" somehow (for example, we could rename the package to
alex-garbage in the database, keeping the non-removed files in its
filelist), but that would definitely violate KISS and it would be not so
easy to implement (directories are also listed in the filelist of a
package, possible conflicts of garbage packages, etc.).

I cannot see a clean "filesystem check" solution neither.

NG