Bug 664940 – sys-apps/portage: File-directory replacement behavior leaves cruft on the filesystem

• Product: Portage Development
• Status: CONFIRMED ---

[Description Michał Górny 2018-08-31 07:29:26 UTC]

* 
 * Installation of a directory is blocked by a file:
 *   '/usr/lib64/gimp/2.0/plug-ins/web-browser'
 * This file will be renamed to a different name:
 *   '/usr/lib64/gimp/2.0/plug-ins/web-browser.backup.0000'
 * 

Portage does not take care of managing/recording the 'backup' appropriately, and therefore anytime this occurs, users are left with a lot of cruft that won't be cleaned up automatically and that requires full manual intervention.  Furthermore, given that PMS specifically forbids doing this, developers aren't warned of the problem in time and ebuilds with such breakage are deployed to a lot of our user systems.

My suggestion would be to detect this kind of file collisions early, and fail hard when they happen.

[Comment 1 Zac Medico 2018-09-01 04:27:34 UTC]

(In reply to Michał Górny from comment #0)
> My suggestion would be to detect this kind of file collisions early, and
> fail hard when they happen.

I suppose the natural way to resolve it would be a hard blocker? This could lead to difficult situations if critical system packages are involved, since it might not be practical to uninstall them in advance.

An alternative might be to have some kind of central registry for things that have to be moved for some reason, kind of like portage's preserve-libs registry.

[Comment 2 Michał Górny 2018-09-01 05:36:55 UTC]

A hard blocker or pkg_preinst() magic, I suppose.

[Comment 3 Zac Medico 2018-09-01 09:21:15 UTC]

Maybe something like this for pkg_preinst() magic:

src_install() {
	emake DESTDIR="${D}" install

	# Rename directory in ED, in order to bypass collision
	# protection and handle it manually.
	mv "${ED}/foo/bar"{,.new} || die
}

pkg_preinst() {
	# Remove file in EROOT that the directory collides with.
	rm -f "${EROOT}/foo/bar" || die

	# Following the collision protection check, reverse
	# src_install's rename in ED.
	mv "${ED}/foo/bar"{.new,} || die
}