deborphan and cruft

[Snowhog]

man deborphan

DESCRIPTION
deborphan finds packages that have no packages depending on them. The
default operation is to search only within the libs and oldlibs sec‐
tions to hunt down unused libraries.

If it is invoked with an optional list of packages, only the dependen‐
cies on those packages will be checked. The results are printed to std‐
out as if the option --show-deps had been given. Searching for specific
packages will show the package, regardless of its priority. It is pos‐
sible to specify -, to read a list of packages from standard input.

man cruft

DESCRIPTION
This manual page documents briefly the cruft command. Please see
/usr/share/doc/cruft/README.gz for more information.

cruft is a program that goes over the Debian packaging system's data‐
base, and compares the contents of that with the files actually on your
system, and produces a summary of the differences.

Just how accurate are these two utilities at identifying unneccessary items on your system? Running deborphan on my system (Karmic KDE 4.4.1) reports:

w32codecs
libkexiv2-7
libavcodec-unstripped-52
libdns50
libsnmp15
libscim8c2a
libk3b6-extracodecs
libtunepimp5-mp3
libstrigiqtdbusclient0
soprano-backend-sesame

deborphan --guess-data identifies one additional item:

hplip-data

deborphan --guess-all identifies:

amarok-dbg
w32codecs
libkexiv2-7
libkorundum4-ruby1.8
libavcodec-unstripped-52
python-sip4
kdebase-runtime-data-common
kdebase-runtime-bin-kde4
libdns50
libsnmp15
libscim8c2a
libk3b6-extracodecs
libtunepimp5-mp3
libstrigiqtdbusclient0
python-imaging
hplip-data
soprano-backend-sesame

I then ran cruft wih the -r option (output to a file) and the results are significant.

I like having a 'clean' system, one that doesn't have bits and pieces of leftover, un-needed 'junk.' So, can I 'trust' the results of these two utilities?

[kubicle]

Re: deborphan and cruft

So, can I 'trust' the results of these two utilities?

You can generally trust deborphan in identifying packages that no other packages depend on, but you may still want to keep some of the packages even though nothing depends on them...in your list w32codecs and libk3b6-extracodecs are packages you may wish to keep (even if they are not actually necessary).

Many of the other packages identified as "unnecessary" are likely either transitional packages that ensure a replacing package is installed (like libavcodec-unstripped-52 --> libavcodec-extra-52 and kdebase-runtime-bin-kde4 --> kdebase-runtime), or are superseded by a differently named newer version (like libdns50 --> libdns53 or libdns64 and libkexiv2-7 --> libkexiv2-8), or simply dependencies that are no longer required (like hplip-data, libsnmp15 and python-imaging which are all dependencies of the hplip package that you have probably removed). These can generally be safely removed.

If unsure, I'd recommend inspecting the packages in your package manager...you can create a custom filter in synaptic to filter out "orphaned" packages for easy review.

In short, the packages reported by deborphan are generally safe to remove, but you may still not want to remove them all.

I can't speak for 'cruft', never used it, but the package description mentions it is pre-released software so I wouldn't trust it blindly...could still be useful though.

[Snowhog]

Re: deborphan and cruft

Thank you. A clear explanation.

[Rog131]

Re: deborphan and cruft

I like having a 'clean' system, one that doesn't have bits and pieces of leftover, un-needed 'junk.' So, can I 'trust' the results of these two utilities?

Yes and no

You need to check the suggestions. Here (KK / KDE 4.3) the deborphan tells:

:~$ deborphan
iwidgets4
libdns50
soprano-backend-sesame

soprano-backend-sesame is needed at here.

The deborphan --guess-all is finding the dev and dbg packages as orphans:

deborphan --guess-all
libkdcraw7-dev
libavformat-dev
libkipi6-dev
libxine-dev
libhd-dev
libkcddb-dev
iwidgets4
libffmpegthumbnailer-alternative-dev
libexiv2-dev
libmarble-dev
plasma-dataengines-addons-dev
libknotificationitem-dev
libdns50
kdebase-workspace-dbg
libqimageblitz-dev
kdebase-workspace-dev
...
libsox-fmt-mp3
xorg-dev
soprano-backend-sesame

This is a known issue > Removing unnecessary packages with deborphan:

Most of the packages it reports are development packages, not required per se, but required if you wish to build things from source and link against package libraries.

Also the libsox-fmt-mp3 / SoX MP3 format library is needed at here.


A Ubuntu (GTK) how to > Cleaning up a Ubuntu GNU/Linux system