Arch Linux

I am able to reproduce it. However, my update didn't cause this. Maybe pacman tries to remove and recreate that dir for some reason. (filelist and permission of the old and new package are identical)

adding more guys; not sure if this is a packaging or pacman issue.

So an upgrade operation is just a remove followed by an install. Pacman is seeing /media/cd/ as empty so attempting to remove the directory before creating it again. Not sure why pacman is seeing that directory as empty when a data CD is mounted.

In this case it is harmless anyway.

However, in general I think directories like /media/cd or /media/fd shouldn't be provided by the filesystem package.

Looking into this, it is because /media/cd becomes ro when a cd gets mounted. Pacman checks all files/folders that are being updated are rw (excluding files in the backup array which do not get touched).

Two options to fix:
1) remove those folders from the filesystem package (as Pierre suggests)
2) from the pacman side: Perhaps directories that are in both the old and new packages should be skipped in the rw check. We do not fail on an attempted delete of a directory anyway as we assume it contains files from other packages. But it will give the usual directory permissions differ blurb.

These options do not clarify whether it is a packaging issue or a pacman issue or both...

We'd lose the whole benefit of this checking if we went with 2. It is there so one can be notified if say /var/lib/privatedata is 700 in the package but 755 on your filesystem. Chances of this folder being new are not that high.

Not that checking. Just the checking in "can_remove_file" in lib/libalpm/remove.c

/* If we fail write permissions due to a read-only filesystem, abort.
* Assume all other possible failures are covered somewhere else */

We could skip that check for _folders_ that are in both the old and the new package as they do not need removed.

Edit: or at least it does not matter if they are failed to be removed as is shown later in remove.c...

if(S_ISDIR(buf.st_mode)) {
if(rmdir(file)) {
/* this is okay, other packages are probably using it (like /usr) */
...

Aha! Yes, that is correct.

I have removed the /media/* mount points for the next filesystem release.

Can we close this or move it to the pacman bug tracker then?

Opened  FS#21971  for tracking this in pacman.