Cupt tutorial

Eugene V. Lyubimkin
20110729



PREFACE

Abstract

Cupt is a high-level package manager for Debian and Debian-derived OSes, with dpkg(1) as a back-end.

The aim of this manual is to describe the all features Cupt package manager has to manage the system, from the most basics to very advanced tuning. Please submit your proposals/patches when you see some use case is not covered.

This manual was written for the second major version of Cupt (2.x branch). Most of it is however applicable to first major version (1.x branch) too.

Disadvantages and advantages

You might not want to use Cupt, because:

You might want to use Cupt to have these, to my best knowledge, unique features:

Also, one of Cupt's targets is to have zero non-wishlist bugs. You might want to try it if you encountered a bug in other package manager(s).

Getting started

To start working with Cupt just install it using any present package manager, for example apt-get install cupt or aptitude install cupt.

Cupt uses existing APT infrastructure for the work. It should be safe to co-use Cupt and any APT-based package managers.

Note: since version 2.1.0, Cupt uses its own directory for repository index lists, so apt-get update, aptitude update etc. do not change Cupt index data anymore.

When using commands that modify a system, you have to either execute cupt with root priviledes or supply --simulate (or -s) option.

Use cupt help to get a list of subcommands and their short descriptions.

BASICS

The debian system as Cupt sees it

Cupt package manager sees the Debian system as a set of installed packages and repositories of available packages.

Each binary package has zero, one or more versions, of which zero or one versions may be installed.

Any installed package may be marked as automatically installed, it means that user didn't ask for this package to be installed, but it is needed to satisfy some dependency. Packages which are not automatically installed are manually installed.

Available versions (including installed one) of the binary package have unique version strings.

Errors and warnings

Cupt uses three types of output to user: information, warnings and errors.

All warning messages are prepended with W:. They mean non-critical errors, which may be, depending on the situation, real errors or things to ignore.

All error messages are prepended with E:. Most of errors block the executing of the program, but not all.

Errors and warnings are written to the standard error.

All other messages are the information for the user. They are written to standard output.

Exploring the system

what packages are installed?

  cupt pkgnames --installed-only

gives you the list, one package name per line. You can also use

  dpkg -l | grep "^ii"

for more detailed information.

getting information about an installed package

dpkg -s package_name

or

cupt show --installed-only package_name

A second command is preferrable, for example, when you want to know is this package automatically installed or not.

details of available package versions

To show a default package version:

cupt show package_name

Example: cupt show dpkg

To show all available package versions:

cupt show --all-versions package_name

If you want to see a Debian changelog for a package, use the subcommand changelog.

Example: cupt changelog exim4

If you want to see a Debian copyright file a for a package, use the subcommand copyright.

Example: cupt copyright exim4

Note: Cupt can show changelogs and copyrights either for installed packages, or for packages available in official repositories in Debian or Ubuntu.

searching for a package

To search for a package, specify one or more regular expressions as arguments:

cupt search keyword1 keyword2 ... keywordN

Example: you want to find a Qt-based audio player:

cupt search audio qt player: found qmmp.

cupt search music qt player: found also amarok.

Another example: you want to find GTK+-related Perl modules:

  cupt search --names-only "gtk.*perl"

Updating repository metadata

To update repository medadata, use

  cupt update

It's recommended to update metadata every time before you install or upgrade packages.

Note: Cupt downloads quite a many files to update repository metadata. Some files may be downloaded in 2-3 different ways (like indexes) or are not so important (like translations for package descriptions). You may see some warnings, but if you don't see an error message like

  E: there were errors while downloading release and index data

, the process overall went fine. You can also check program exit code.

Modifying the system

package actions terminology

When some package is changing its state, Cupt calls the action:

install

when a package which wasn't installed is now going to be installed

remove

when a package will be removed

upgrade

when a new (bigger) version of the already installed package is to be installed

downgrade

when an old (more less) version of the already installed package is to be installed

purge

when a package and its configuration files will be removed

action preview prompt

An example of action preview prompt:

   $ cupt install kdm akregator exim4
   Building the package cache...
   Initializing package resolver and worker...
   Scheduling requested actions...
   Resolving possible unmet dependencies...
   
   The following 7 packages will be INSTALLED:
   
   exim4 exim4-base exim4-config exim4-daemon-light libgnutlsxx26 libntrack-qt4-1
   libntrack0
   
   The following 32 packages will be UPGRADED:
   
   akregator kde-window-manager kdebase-workspace-bin kdebase-workspace-data
   kdebase-workspace-kgreet-plugins kdm ksysguard ksysguardd libgnutls-dev
   libgnutls26 libkdecorations4 libkdepim4 libkephal4 libkscreensaver5 libksgrd4
   libksignalplotter4 libkwineffects1a libkworkspace4 libpcre3
   libplasma-geolocation-interface4 libplasmaclock4a libplasmagenericshell4
   libprocesscore4a libprocessui4a libsolidcontrol4 libsolidcontrolifaces4
   libsoup2.4-1 libtaskmanager4a libweather-ion4a plasma-dataengines-workspace
   plasma-desktop plasma-widgets-workspace
   
   The following 4 packages will be REMOVED:
   
   libgsasl7(a) libntlm0(a) msmtp(a) msmtp-mta
   
   Need to get 25.7MiB/83.4MiB of archives. After unpacking 3512KiB will be used.
   Do you want to continue? [y/N/q/a/?]

In the output above you can see: lists of packages to change the state (with a total number by each action, the total download amount of packages (83.4MiB), the download amount considering the cache of already downloaded archives (25.7MiB), an estimate of difference in disk usage after the actions (+3512KiB), a user prompt what to do.

For removed and purged packages, a suffix (a) is appended to a package name if a package was automatically installed.

The following answers to a user prompt are available:

y

accept a solution, i.e. proceed with it

n

decline a solution, i.e. ask to find another solution

q

don't do anything, quit immediately

?

output a short help about available answers

a

explained here

installing packages

To install a package:

cupt install package_name

Example: cupt install exim4

To install several packages:

cupt install package_name_1 package_name_2 ... package_name_N

Example: cupt install exim4 kvirc kdm

upgrading packages

To upgrade one or more installed packages, use the same commands as for installing packages.

removing packages

To remove a package:

cupt remove package_name

Example:

  cupt remove gdb

To remove several packages:

cupt remove package_name_1 package_name_2 ... package_name_N

Example:

  cupt remove gdb kvirc exim4

upgrading the whole system

To upgrade as many packages as possible:

  cupt full-upgrade

In the mode above, Cupt will even consider removing manually installed packages. If you want to restrict removing manually installed packages, do

  cupt full-upgrade --no-remove

Or, shorter:

  cupt safe-upgrade

There is the third upgrade mode, which is to be used for upgrades to the next major distribution releases:

  cupt dist-upgrade

This subcommand upgrades Cupt itself and dpkg at first, and then calls new version of itself to upgrade the rest.

purging packages

To purge a package, i.e. remove a package along with its configuration files and maybe some dynamically generated or runtime files:

cupt remove --purge package_name

Or:

cupt purge package_name

To purge several packages:

cupt purge package_name_1 package_name_2 ... package_name_N

Example:

  cupt purge gdb

Package archives cleaning

Whenever Cupt needs to install, upgrade or downgrade packages it downloads binary package archives (.deb files) to an archive cache. These archives are not removed after the first usage so they can be reused later.

If you do upgrades often, it's a good idea to periodically delete old package archives to save the disk space. It's done by the subcommand autoclean:

  cupt autoclean

The command above will delete all package archives which do not belong to currently available repositories.

If you want to remove all archives from the cache, do

  cupt clean

INTERMEDIATE LEVEL

Working with multiple package versions

changing repositories

Cupt uses the same repository list format as APT. See sources.list(5).

release information

Each version of a certain package has one or more sources where it comes from.

Each source consists of download information and a subrepository information, or release information.

The following properties belong to release information:

basic URI

a common prefix of URIs for all files which come for this (sub)repository (also referred as origin in APT documentation)

Example: http://ftp.fi.debian.org/debian

archive

a repository archive name, for example testing or stable

codename

a release code name, for example wheezy or sid

component

a subrepository component name, for example main or non-free

vendor

a vendor name, for example: Debian

label

a vendor-provided label, for example: Debian-Security

version

a release version, for example: 6.0

description

a repository description line

Any of properties above may be empty.

To see available releases:

  cupt policy

Example:

   $ cupt policy
   Package files:
     /var/lib/dpkg/status installed/: o=dpkg,a=installed,l=,c=,v=,n=now
     http://ftp.fi.debian.org/debian stable/main: o=Debian,a=stable,l=Debian,c=main,v=6.0,n=squeeze
     http://security.debian.org stable/main: o=Debian,a=stable,l=Debian-Security,c=main,v=6.0,n=squeeze
     http://ftp.fi.debian.org/debian squeeze-updates/main: o=Debian,a=squeeze-updates,l=Debian,c=main,v=,n=squeeze-updates
     http://ftp.fi.debian.org/debian testing/main: o=Debian,a=testing,l=Debian,c=main,v=,n=wheezy
     http://ftp.fi.debian.org/debian testing/contrib: o=Debian,a=testing,l=Debian,c=contrib,v=,n=wheezy
     http://ftp.fi.debian.org/debian testing/non-free: o=Debian,a=testing,l=Debian,c=non-free,v=,n=wheezy
     http://ftp.fi.debian.org/debian unstable/main: o=Debian,a=unstable,l=Debian,c=main,v=,n=sid
     http://ftp.fi.debian.org/debian unstable/contrib: o=Debian,a=unstable,l=Debian,c=contrib,v=,n=sid
     http://ftp.fi.debian.org/debian unstable/non-free: o=Debian,a=unstable,l=Debian,c=non-free,v=,n=sid
     http://ftp.fi.debian.org/debian experimental/main: o=Debian,a=experimental,l=Debian,c=main,v=,n=experimental

The format of lines above:

basic_URI archive/component: o=vendor,a=archive,l=label,c=component,v=version,n=codename

Note that "installed" release have the archive installed and the codename now.

To see the release descriptions of releases a version belongs to:

cupt show --with-release-info package_name

Example:

  cupt show --with-release-info dpkg

version pinning system

Each package version has a pin, an integer number. Amongst all versions of the same binary package, the one who has maximal pin is policy, or candidate version.

Cupt assigns pins to package versions according to the APT documentation (apt_preferences(5)). Plus, it adds:

Note that sometimes the way APT assigns pins to versions is not the way described in its documentation, so Cupt's pins (modulo Cupt-specific additions described above) are not necessarily identical to what APT produces.

what package versions are available?

cupt policy package_name

Example:

   $ cupt policy dpkg
   dpkg:
     Installed: 1.15.5.6
     Candidate: 1.15.8.10
     Version table:
        1.15.8.10 991
           http://ftp.fi.debian.org/debian testing/main (signed)
           http://ftp.fi.debian.org/debian unstable/main (unsigned)
           http://ftp.se.debian.org/debian testing/main (signed)
           http://ftp.se.debian.org/debian unstable/main (signed)
    *** 1.15.5.6 100
           /var/lib/dpkg/status installed/ (unsigned)
        1.14.31 -1499
           http://security.debian.org oldstable/main (signed)

In the output above we can see: installed version ('1.15.5.6'), candidate version ('1.15.8.10') and a version table. In total, 3 versions of dpkg are available.

For each version in version table we can see (on example of '1.15.8.10'): a version pin ('991'), a list of repositories where this version is available.

Each repository line is:

basic_URI archive/component (signeness)

The repository marked as signed if it has a valid and verified cryptographic signature, and unsigned otherwise.

selecting binary package versions

When there are more than one version for a package, Cupt provides following ways to select a version of the binary package in the arguments of the various subcommands:

policy version

to select a policy version, just specify a package name alone.

Example:

  cupt show dpkg

specific version

to select an exact version of the package, use the suffix =version.

Example:

  cupt show dpkg=1.15.8.10

by archive or codename

to select a version in release with known archive or codename, use the suffix /archive or /codename.

Examples:

  cupt show dpkg/unstable

  cupt show dpkg/sid

The syntax described above is known as binary package version expression. In the cupt(1) manual page all subcommands which accept this syntax are clearly marked as such.

Combining multiple version arguments

Many subcommands accept several arguments of the same meaning. Examples:

  cupt show dpkg cupt libpqxx3=3.0.2-1>
  cupt install youtube-dl clive/stable
  cupt remove libabc-dev libefg-dev libxyz-dev
  cupt policy perl perl-base

You can use wildcards * and ? to select multiple package names. Examples:

Also, some subcommands accept arguments' special modifiers:

+

"install this"

-

"remove this"

You can use the + modifier in subcommands: remove, purge. Examples:

cupt remove youtube-dl clive+: remove youtube-dl, install clive

cupt purge exim4 msmtp-mta+ mutt/experimental+: remove exim4 along with its configuration files, install msmtp-mta and mutt (from experimental)

You can use the - modifier in the install and *-upgrade-like subcommands. Examples:

cupt install gnuchess/unstable gnome-chess pychess-: install gnuchess (from unstable), gnome-chess, remove pychess

cupt full-upgrade cvs-:

a) cvs is installed -> do an upgrade with removing cvs

b) cvs is not installed -> do an upgrade, keeping cvs uninstalled

Using package archive deltas

Cupt has an integration (through a special download method) with debdelta(1). To make Cupt try to download archive deltas before downloading full archives, just install the package debdelta and that's it. No manual invocation of debdelta utilities is needed.

See more about debdelta project here: http://debdelta.debian.net/.

Listing dependency information

To list the dependencies of one or more package versions, use the subcommand depends:

  cupt depends libc6/testing arora/unstable

If you don't want to see Recommends there, use --important:

  cupt depends --important libc6/testing

If, on the contrary, you want to see even Suggests, use --with-suggests:

  cupt depends --with-suggests libc6/testing

You can also list selected relations recursively, using --recurse:

  cupt depends --recurse dpkg

If you want to see a reverse dependencies of some version, use the subcommand rdepends:

  cupt rdepends xz-utils

All the command switches described here are also applicable to rdepends as well.

Action preview prompt (extended)

detailed solution preview

You can request more information to show in the action preview prompt:

You can also combine them.

specifying more package expression arguments

In a solution preview (action preview prompt) you have an ability to specify more package expressions and a restart a resolving process. To do this, use the choice a. Example:

   $ cupt install gnash
   Building the package cache...
   Initializing package resolver and worker...
   Scheduling requested actions...
   Resolving possible unmet dependencies...
   
   The following 64 packages will be INSTALLED:
   
   dmsetup dosfstools freepats fuse-utils gconf2-common gnash gnash-common
   gstreamer0.10-ffmpeg gstreamer0.10-fluendo-mp3 gstreamer0.10-plugins-bad
   gstreamer0.10-plugins-base gvfs hdparm libass4 libatasmart4
   libboost-thread1.42.0 libcdaudio1 libcelt0-0 libexempi3 libexif12 libfftw3-3
   libflite1 libfuse2 libgconf2-4 libgdu0 libgme0 libgnome-keyring0 libgsf-1-114
   libgsf-1-common libgtkglext1 libgudev-1.0-0 libidl0 libiptcdata0 libkate1
   liblvm2app2.2 libmimic0 libmms0 libmodplug1 libmusicbrainz4c2a libntfs-3g75
   libntfs10 libofa0 libopenspc0 liborbit2 liborc-0.4-0 libparted0debian1
   libpolkit-backend-1-0 libraptor2-0 librasqal3 librsvg2-2 libsgutils2-2
   libslv2-9 libsoundtouch0 libvisual-0.4-0 libvisual-0.4-plugins libwildmidi1
   libyajl1 libzbar0 mtools ntfs-3g ntfsprogs policykit-1 policykit-1-gnome udisks
   
   The following 12 packages will be UPGRADED:
   
   libblkid1 libdbus-glib-1-2 libdevmapper1.02.1 libglib2.0-0
   libgstreamer-plugins-base0.10-0 libgstreamer0.10-0 libpcre3 libpolkit-agent-1-0
   libpolkit-gobject-1-0 librdf0 libschroedinger-1.0-0 libudev0
   
   The following 2 packages will be REMOVED:
   
   libeggdbus-1-0(a) librasqal2(a)
   
   Need to get 62.3MiB/62.3MiB of archives. After unpacking 105MiB will be used.
   Do you want to continue? [y/N/q/a/?] a
   Enter a package expression (empty to finish): libgnome-keyring0-
   Enter a package expression (empty to finish):
   
   The following 39 packages will be INSTALLED:
   
   freepats gnash gnash-common gstreamer0.10-ffmpeg gstreamer0.10-fluendo-mp3
   gstreamer0.10-plugins-bad gstreamer0.10-plugins-base libass4
   libboost-thread1.42.0 libcdaudio1 libcelt0-0 libexempi3 libexif12 libfftw3-3
   libflite1 libgme0 libgsf-1-114 libgsf-1-common libgtkglext1 libgudev-1.0-0
   libiptcdata0 libkate1 libmimic0 libmms0 libmodplug1 libmusicbrainz4c2a libofa0
   libopenspc0 liborc-0.4-0 libraptor2-0 librasqal3 librsvg2-2 libslv2-9
   libsoundtouch0 libvisual-0.4-0 libvisual-0.4-plugins libwildmidi1 libyajl1
   libzbar0
   
   The following 7 packages will be UPGRADED:
   
   libglib2.0-0 libgstreamer-plugins-base0.10-0 libgstreamer0.10-0 libpcre3
   librdf0 libschroedinger-1.0-0 libudev0
   
   The following 1 packages will be REMOVED:
   
   librasqal2(a)
   
   Leave the following dependencies unresolved:
   
   gstreamer0.10-plugins-base 0.10.30-1 recommends 'gvfs'
   
   Need to get 56.2MiB/56.2MiB of archives. After unpacking 85.6MiB will be used.
   Do you want to continue? [y/N/q/a/?]

The effect above is the same as if you specified

  cupt install gnash libgnome-keyring0-

in the command line from the start.

Adjusting configuration variables

There are two types of configuration variables - regular (or scalar) and list ones. Scalar options have a single scalar value, and list option's value is a list of strings. Modifying a scalar option means substituting its previous value completely in favor of new specified one, modifying a list option means adding one more string to the existing list.

Cupt has many configuration variables, some of them may be specified/overridden using command-line switches, some needs to be modified explicitly. See the full variable list and descriptions at cupt(1)/Configuration variables.

To see the current configuration, use config-dump subcommand. Examples:

   $ cupt config-dump | grep recommends
   apt::install-recommends "yes";
   cupt::resolver::keep-recommends "yes";
   cupt::resolver::tune-score::failed-recommends "600";
   $ cupt config-dump | grep "methods "
   cupt::downloader::protocols::copy::methods { "file"; };
   cupt::downloader::protocols::debdelta::methods { "debdelta"; };
   cupt::downloader::protocols::file::methods { "file"; };
   cupt::downloader::protocols::ftp::methods { "curl"; };
   cupt::downloader::protocols::ftp::methods { "wget"; };
   cupt::downloader::protocols::http::methods { "curl"; };
   cupt::downloader::protocols::http::methods { "wget"; };
   cupt::downloader::protocols::https::methods { "curl"; };
   cupt::downloader::protocols::https::methods { "wget"; };

You can distingiush list options there by figure brackets around the values.

Cupt reads configuration first from files (conforming to the APT documentation (apt.conf(5))), then applies those specified in the command line using --option (or -o) switch or by dedicated switches corresponding to the option.

To modify a regular option in the command line, use

-o option_name=new_value

Example:

  cupt install kmail -o cupt::console::assume-yes=yes

To modify a list option (i.e. add a new string) in the command line, use

-o option_name::=added_string

Example:

  cupt -s update -o "apt::update::pre-invoke::=ls /var"

You can use -o multiple times.

Automatically installed packages

view

If you want to know, is a certain package automatically installed or not, do

cupt show --installed-only package_name

Example:

  cupt show --installed-only dpkg

To list manually installed packages:

  cupt showauto --invert

To list automatically installed packages:

  cupt showauto

change

To mark some package(s) as automatically installed, use the markauto subcommand, for example:

  cupt markauto libqtcore4 udev

To mark some package(s) as manually installed, use the unmarkauto subcommand, for example:

  cupt unmarkauto tar traceroute

removal

When doing installs/upgrades/etc. all newly installed packages not requested by user are marked as automatically installed. For every package management actions Cupt's resolver can determine if some automatically installed packages are not needed anymore. Automatically installed packages, which are no more a part of any valuable dependency chain of manually installed packages, are deleted by default. The names of this process is auto-removal.

If you don't want auto-removal to be performed, use --no-auto-remove switch or set the option cupt::resolver::auto-remove to no.

Soft dependencies

All forward interdependencies between packages can be divided into two groups -- hard and soft ones. While hard dependencies must be satisfied in order to make a system (or proposed solution) valid, soft ones may stay unsatisfied. Hard dependencies are 'Pre-Depends', 'Depends'. Soft dependencies are 'Recommends', 'Suggests' and 'Enhances'. Cupt completely ignores 'Enhances', but can act on 'Recommends' or 'Suggests'. All the remainder of this section is dedicated to the last two.

By default, Cupt ignores 'Suggests', but tries to, with an average priority, satisfy new dependencies in 'Recommends' and keep already satisfied 'Recommends'.

You can use the following options to change the behavior:

apt::install-recommends

set this to no to not satisfy new 'Recommends'. See also the command-line switch --no-install-recommends.

cupt::resolver::keep-recommends

set this to no to make resolver ignore all 'Recommends'

apt::install-suggests

set this yes to make resolver try to satisfy new 'Suggests'

cupt::resolver::keep-suggests

set this to yes to make resolver try to keep already satisfied 'Suggests'

Note 1: having the option apt::install-X set to yes without cupt::resolver::keep-X set to yes as well is useless, Cupt's native resolver will warn about it.

Note 2: even when the appropriate apt::install-X option is set, Cupt ignores not changed soft dependencies. Say, if there is an installed package gettext of version 1.2 which Recommends: cvs, a relation cvs is not satisfied in the system, and gettext is upgraded to a version 1.3 which also have the same Recommends: cvs, Cupt won't try to satisfy this dependency.

Understanding package installation process

After you agree with a proposed solution (by entering a positive answer in an action preview prompt) Cupt starts a package installation process, which is done in several phases:

  1. preparation

    In this phase Cupt computes the order in which dpkg(1) will called and the options to pass. This phase may take a while for large changes.

  2. downloading

    In this phase Cupt downloads needed binary packages (*.deb). May be empty if no packages are needed or all needed packages are already in the cache.

  3. pre-hooks

    In this phase Cupt calls registered pre-hooks (options dpkg::pre-invoke and dpkg::pre-install-pkgs) if any. Examples of them are apt-listchanges(1), apt-listbugs(1) and dpkg-preconfigure(1). These hooks may ask questions and cancel the whole package installation process.

  4. action themselves

    In this phase Cupt calls dpkg as many times as needed to perform requested actions.

  5. post-hooks

    In this phase Cupt calls registered post-hooks (the option dpkg::post-invoke) if any.

Note: Cupt itself does not ask anything from the user during the package installation process. All questions usually come from programs which Cupt calls.

Example:

   1: # cupt install cmake
   2: Building the package cache...
   3: Initializing package resolver and worker...
   4: Scheduling requested actions...
   5: Resolving possible unmet dependencies...
   6:
   7: The following 4 packages will be INSTALLED:
   8:
   9: libarchive1 libcurl3 libssh2-1 libxmlrpc-core-c3
   10:
   11: The following 2 packages will be UPGRADED:
   12:
   13: cmake cmake-data
   14:
   15: Need to get 5637KiB/6007KiB of archives. After unpacking 1963KiB will be freed.
   16: Do you want to continue? [y/N/q/a/?] y
   17: Performing requested actions:
   18: Get:1 http://ftp.fi.debian.org/debian wheezy/main,sid/main,wheezy/main,sid/main cmake-data 2.8.4+dfsg.1-2 [1224KiB]
   19: Get:2 http://ftp.fi.debian.org/debian wheezy/main,sid/main,wheezy/main,sid/main cmake 2.8.4+dfsg.1-2 [4102KiB]
   20: Get:3 http://ftp.fi.debian.org/debian wheezy/main,sid/main,wheezy/main,sid/main libarchive1 2.8.4-1 [149KiB]
   21: Get:4 http://ftp.fi.debian.org/debian wheezy/main,sid/main,wheezy/main,sid/main libxmlrpc-core-c3 1.16.33-2 [162KiB]
   22: Fetched 5637KiB in 1s.
   23: Reading changelogs... Done
   24: Selecting previously deselected package libarchive1.
   25: (Reading database ... 94022 files and directories currently installed.)
   26: Unpacking libarchive1 (from .../libarchive1_2.8.4-1_i386.deb) ...
   27: Setting up libarchive1 (2.8.4-1) ...
   28: Processing triggers for man-db ...
   29: Selecting previously deselected package libssh2-1.
   30: (Reading database ... 94034 files and directories currently installed.)
   31: Unpacking libssh2-1 (from .../libssh2-1_1.2.6-1_i386.deb) ...
   32: Setting up libssh2-1 (1.2.6-1) ...
   33: Selecting previously deselected package libcurl3.
   34: (Reading database ... 94041 files and directories currently installed.)
   35: Unpacking libcurl3 (from .../libcurl3_7.21.3-1_i386.deb) ...
   36: Setting up libcurl3 (7.21.3-1) ...
   37: Selecting previously deselected package libxmlrpc-core-c3.
   38: (Reading database ... 94058 files and directories currently installed.)
   39: Unpacking libxmlrpc-core-c3 (from .../libxmlrpc-core-c3_1.16.33-2_i386.deb) ...
   40: Setting up libxmlrpc-core-c3 (1.16.33-2) ...
   41: (Reading database ... 94080 files and directories currently installed.)
   42: Removing cmake ...
   43: Processing triggers for man-db ...
   44: (Reading database ... 94071 files and directories currently installed.)
   45: Preparing to replace cmake-data 2.8.1-2 (using .../cmake-data_2.8.4+dfsg.1-2_all.deb) ...
   46: Unpacking replacement cmake-data ...
   47: Setting up cmake-data (2.8.4+dfsg.1-2) ...
   48: emacsen-common: Handling install of emacsen flavor emacs
   49: Processing triggers for man-db ...
   50: Selecting previously deselected package cmake.
   51: (Reading database ... 94087 files and directories currently installed.)
   52: Unpacking cmake (from .../cmake_2.8.4+dfsg.1-2_i386.deb) ...
   53: Setting up cmake (2.8.4+dfsg.1-2) ...
   54: Processing triggers for man-db ...

In the output above:

   2-5: information messages
   7-16: action preview prompt
   17: phase 'preparation'
   18-22: phase 'downloading'
   23: phase 'pre-hooks' (namely, apt-listchanges)
   24-54: phase 'action themselves', dpkg's output

In the case the process fails at phase 'action themselves' (either due to bug in Cupt, dpkg, or packages), you'll see some error messages from dpkg and then error messages from Cupt.

Source packages

overview

Source packages are the files from which binary packages are built. They have two major differences:

exploring

To view a source package information:

cupt showsrc package_name

Example:

  cupt showsrc cupt

You can specify more than one package, for example:

  cupt showsrc sed mawk

To view available source versions, pin info and releases versions come from, use policysrc subcommand. Its output is the same as for policy subcommand. Example:

  cupt policysrc sed mawk

To download source package(s), use the source subcommand, for example:

  cupt source clive youtube-dl

By default source subcommand also unpack the package so it's ready for the exploring and building. To prevent this, use the --download-only switch. Also, you can download only one part of source package, use switches --tar-only, --diff-only and --dsc-only for that.

satisfying build dependencies

If you want to build binary packages out of a source one, you will have to satisfy source package's build dependencies before. Use the subcommand build-dep to do it, for example:

  cupt build-dep clive

All new packages, installed by this subcommand, will be marked as automatically installed, and will be a subject for auto-removal at next package management action.

So, the process of building binary packages out of source one may be, taking clive package as an example:

   cupt source clive
   cupt build-dep clive
   cd clive-2.2.13 && debuild && cd ../
   [...]
   cupt install

The last line will remove all unneeded anymore packages (given auto-removal is turned on), including those installed by build-dep.

selecting source package versions

You can select source package versions in two ways:

  1. Provide a source package version expression. It has the same syntax as binary package version expression, but instead of specifying a binary package name you specify a source package name.

    Example:

      cupt showsrc game-music-emu=0.5.5-2 gcc-defaults/experimental
    

  2. Provide a binary package version expression, which will be converted to a source package version expression when possible.

    Example:

       $ cupt show g++/experimental | head -n5
       Package: g++
       Version: 4:4.6.0-2exp1
       Status: not installed
       Source: gcc-defaults
       Source version: 1.101exp1
       $ cupt showsrc g++/experimental | head -n3
       Package: gcc-defaults
       Binary: cpp, g++, g++-multilib, gobjc, gobjc-multilib, gobjc++,
       gobjc++-multilib, gfortran, gfortran-multilib, gccgo, gccgo-multilib,
       libgcj-common, gcj, gij, libgcj-bc, gcj-jdk, gcj-jre-headless, gcj-jre, gcc,
       gcc-multilib, gdc, gcc-spu, g++-spu, gfortran-spu
       Version: 1.101exp1
    

    Here, g++ is a binary package name and gcc-defaults is a source package name. In the second command, as there is no source package g++, a binary package was looked up, a version 4:4.6.0-2exp1 of it was found, and then a source version was selected as if you specified

      cupt showsrc gcc-defaults=1.101exp1
    

    in the first place.

You can supply both syntaxes to all subcommands which work with source package versions, examples:

  cupt build-dep clive/unstable
  cupt source man-db=2.5.9-4>

Package manager shell

Cupt has a shell-like environment, in which you can supply any subcommand as if you typed it in to the command line, but without preceding cupt command name.

Example:

   $ cupt shell
   This is interactive shell of cupt package manager.
   Building the package cache... [done]
   cupt>policy libsoprano4
   libsoprano4:
     Installed: 2.2.2+dfsg.1-1
     Candidate: 2.3.0+dfsg.1-2
     Version table:
        2.3.0+dfsg.1-2 501
          http://debian.org.ua/debian unstable/main (signed)
    *** 2.2.2+dfsg.1-1 100
          /var/lib/dpkg/status installed/ (unsigned)
        2.3.0+dfsg.1-1 2
          http://debian.org.ua/debian experimental/main (signed)
   cupt>depends libsoprano4/experimental
   libsoprano4 2.3.0+dfsg.1-1:
     Depends: libc6 (>= 2.2.5)
     Depends: libclucene0ldbl (>= 0.9.20-1)
     Depends: libgcc1 (>= 1:4.1.1)
     Depends: libqt4-dbus (>= 4:4.5.2)
     Depends: libqt4-network (>= 4:4.5.2)
     Depends: libqt4-xml (>= 4:4.5.2)
     Depends: libqtcore4 (>= 4:4.5.2)
     Depends: libstdc++6 (>= 4.1.1)
     Depends: soprano-daemon (= 2.3.0+dfsg.1-1)
   cupt>rdepends soprano-daemon
   soprano-daemon 2.3.0+dfsg.1-2:
     Reverse-Depends: libsoprano4 2.3.0+dfsg.1-2: soprano-daemon (= 2.3.0+dfsg.1-2)
   cupt>show soprano-daemon
   Package: soprano-daemon
   Version: 2.3.0+dfsg.1-2
   Status: not installed
   Source: soprano
   Priority: optional
   Section: utils
   Size: 153KiB
   Uncompressed size: 536KiB
   Maintainer: Debian Qt/KDE Maintainers <debian-qt-kde@lists.debian.org>
   Architecture: amd64
   Depends: libc6 (>= 2.2.5), libgcc1 (>= 1:4.1.1), libqt4-dbus (>= 4:4.5.2), libqt4-network (>= 4:4.5.2),
   libqtcore4 (>= 4:4.5.2), libraptor1 (>= 1.4.18), librdf0 (>= 1.0.9), libsoprano4 (>= 2.3.0), libstdc++6 (>= 4.1.1)
   Conflicts: libsoprano-dev (<< 2.3.0+dfsg.1-1), libsoprano4 (<< 2.3.0+dfsg.1-1)
   Replaces: libsoprano-dev (<< 2.3.0+dfsg.1-1), libsoprano4 (<< 2.3.0+dfsg.1-1)
   URI: http://debian.org.ua/debian/pool/main/s/soprano/soprano-daemon_2.3.0+dfsg.1-2_amd64.deb
   MD5: af29b39a741d9a52de91c8e5562e0609
   SHA1: 1dfebe27b79f10911358949e56f89c64b43265eb
   SHA256: d5b290a60de56f6a7e0af44f5265c6668bb4689204556b9022a5233a808349fc
   Description: daemon for the Soprano RDF framework
    Soprano is a pluggable RDF storage, parsing, and serialization framework based
    on Qt 4. Soprano is targeted at desktop applications that need to store RDF
    data. Its API has been optimized for simplicity and ease of use, while its
    modular structure allows it to use various different RDF storage
    implementations as its backend.
    .
    This package contains the Soprano daemon, D-Bus service, parser
    plugins, and a storage plugin for the Redland RDF Application Framework.
   Homepage: http://soprano.sourceforge.net
  
   cupt>--simulate install libsoprano4
   Building the package cache... [done]
   Initializing package resolver and worker... [done]
   Scheduling requested actions... [done]
   Resolving possible unmet dependencies... 
   The following 1 packages will be INSTALLED:
  
   soprano-daemon 
  
   The following 1 packages will be UPGRADED:
  
   libsoprano4 
  
   Need to get 700KiB/700KiB of archives. After unpacking 196KiB will be used.
   Do you want to continue? [y/N/q] q
  
   cupt>exit

What this mode may be useful for:

ADVANCED USAGE

System snapshots

System snapshots, created by Cupt, consist of binary archives of installed packages. The idea is you create snapshots at some time, and when after some changes you system is messed up, you can go back to the working set of packages.

Caveats:

It's recommended not to use this feature if you have better alternatives available (for example, LVM snapshots or filesystem-level snapshots).

To create a snapshot, use

cupt snapshot save snapshot_name

Example:

  cupt snapshot save 20110405

To revert the system to a saved snapshot, use

cupt snapshot load snapshot_name

Example:

  cupt snapshot load 20110405

You can also list the available snapshots (cupt snapshot list), rename (cupt snapshot rename), remove (cupt snapshot remove).

Satisfying particular dependency relation expressions

There is an ability to change the system not by specifying versions of packages to install or remove, but by specifying dependencies just as some binary package have them. The subcommand to perform this is satisfy:

cupt satisfy dependency_expression_1 ... dependency_expression_N

Examples:

  cupt satisfy "xserver-xorg (>> 1.6)" "xserver-common (<< 1.6.1~)"
  cupt satisfy "nautilus (>= 2.16.0), libnautilus-extension1 (>= 2.16.0), wget (>= 1.10.0)"
  cupt satisfy "youtube-dl | clive"

If you want some dependency expression to be unsatisfied instead, add minus (-) to the end of an argument:

  cupt satisfy mail-reader-

Be careful:

cupt satisfy vim emacs-: install vim or anything which provides it, remove emacs and anything which provides it

cupt satisfy "vim, emacs-": remove emacs, vim and anything which provides them

Changes in systems with a low disk space

If you happen to have a system, where the disk space is very limited, doing a big upgrades or installations can be a problem. For example, you have 1 GiB of disk space total, installed packages occupy 600 MiB of them, now you want to do a massive upgrade, and it's needed to download 500 MiB of archives to do that, and after the upgrade packages will occupy 700 MiB. Here, the simple approach of download everything needed and then upgrade everything needed wouldn't work since there is no 1100 MiB of the disk space available. The answer is to do the upgrade by smaller parts. Now, although it can be done by selecting groups of packages to upgrade or install by hand, Cupt can try to do it automatically.

To enable the changeset-based mode you will be need specify how many space is available for downloaded files. It's impossible to compute the amount reliably since changed packages may use some additional space (for example, kernel upgrades) or you may write or remove something to the filesystem before/while the upgrading is progressing. A rough guess of 'amount of free space minus 100 MiB' is a good start.

After you computed the disk space you can give for package archives, specify it as a value, in bytes, for cupt::worker::archives-space-limit option. Example:

  cupt full-upgrade -o cupt::worker::archives-space-limit=200000000

Once this option is set, an action scheduler will try to divide all the changes into smaller consequtive changesets so the following conditions are met:

If such changesets are found, Cupt will proceed with actions, otherwise an error with a minimal suitable number will be printed.

For each changeset, package archives will be downloaded before doing actions and removed before the next changeset begins.

Synchronization by source versions

Sometimes it is a good idea to keep installed binary packages which were built out of same source package (let's call them related) to have the same source version.

Related packages are synchronized if they have the same source version, i.e. binary version may not be the same. For example, the following pairs are usually synchronized:

But the following are usually not:

Cupt's resolver tries to synchronize the versions of related binary packages if the option cupt::resolver::synchronize-by-source-versions is set to non-default value.

Note: this option works properly only if you have source packages available for all the packages touched by a resolver.

Note: this option doesn't touch installed packages.

Example:

  cupt safe-upgrade -o cupt::resolver::synchronize-by-source-versions=hard

The hard value means that all changed packages must be synchronized, e.g. consider the synchronization an additional hard dependency. The soft value means that all unsynchronized changed packages will have a penalty of cupt::resolver::score::failed-synchronization, e.g. consider the synchronization as additional soft dependency.

Example:

Suppose we have libfoo1 and foo binary packages which came from the same source package. We have libfoo1 1.2-1 and foo 1.2-1 installed.

Situation 1: libfoo1 has new 1.3-1 version and foo has new 1.3-1 version.

Situation 2: libfoo1 has new 1.3-1 version and foo has new 1.3-2 version.

We do:

  cupt install foo

What would be done by resolver if we have:

Resolver tuning

score

Cupt's native dependency problem resolver plans system changes, if needed, to make installed packages set correct after making the changes user demand.

In the most cases, there are several solutions to a problem. To choose amonst them, resolver assign scores to all of them.

Score is an integer (i.e. can positive and negative) and is a sum of version pin difference (for uninstalled version, zero pin is assumed) and an action modifier. Action modifiers are action type-specific addendums and are controlled by the option group cupt::resolver::score::X (see the full list of them in cupt(1)/Configuration variables).

For native resolver, the negative scores indicate "negative" changes, and positive scores indicate "positive" changes. When several alternative solutions for a problem are available, they are considered in the score descending order. The ultimate goal of score system to assign positive scores to everything user wants and negative scores to everything user don't want. But since "positive" and "negative" is something that varies from user to user and from action to action, there is no (and cannot be) a silver bullet.

So, how can you adjust solution scores? From the definition of the score (above) you may adjust version pinning and/or set resolver score variables to different values.

Examples:

  $ echo 'q' | cupt -s -t experimental full-upgrade | fgrep 'following'
  W: some solutions were dropped, you may want to increase the value of the 'cupt::resolver::max-solution-count' option
  The following 202 packages will be INSTALLED:
  The following 710 packages will be UPGRADED:
  The following 55 packages will be REMOVED:
  Leave the following dependencies unresolved:
  $ echo 'q' | cupt -s -t experimental full-upgrade -o cupt::resolver::score::unsatisfied-recommends=250 | fgrep 'following'
  W: some solutions were dropped, you may want to increase the value of the 'cupt::resolver::max-solution-count' option
  The following 150 packages will be INSTALLED:
  The following 708 packages will be UPGRADED:
  The following 58 packages will be REMOVED:
  Leave the following dependencies unresolved:
  $ echo 'q' | cupt -s -t experimental full-upgrade -o cupt::resolver::score::unsatisfied-recommends=400 | fgrep 'following'
  W: some solutions were dropped, you may want to increase the value of the 'cupt::resolver::max-solution-count' option
  The following 149 packages will be INSTALLED:
  The following 708 packages will be UPGRADED:
  The following 58 packages will be REMOVED:
  Leave the following dependencies unresolved:
  $ echo 'q' | cupt -s -t experimental full-upgrade -o cupt::resolver::score::unsatisfied-recommends=1000 | fgrep 'following'
  W: some solutions were dropped, you may want to increase the value of the 'cupt::resolver::max-solution-count' option
  The following 148 packages will be INSTALLED:
  The following 708 packages will be UPGRADED:
  The following 58 packages will be REMOVED:
  Leave the following dependencies unresolved:
  $ echo 'q' | cupt -s -t experimental full-upgrade -o cupt::resolver::score::new=-1000 | fgrep 'following'
  W: some solutions were dropped, you may want to increase the value of the 'cupt::resolver::max-solution-count' option
  The following 64 packages will be INSTALLED:
  The following 661 packages will be UPGRADED:
  The following 100 packages will be REMOVED:
  Leave the following dependencies unresolved:
  WARNING! The following essential packages will be REMOVED:
  $ echo 'q' | cupt -s -t experimental full-upgrade -o cupt::resolver::score::new=-1000 -o cupt::resolver::score::downgrade=0 | fgrep 'following'
  W: some solutions were dropped, you may want to increase the value of the 'cupt::resolver::max-solution-count' option
  The following 26 packages will be INSTALLED:
  The following 618 packages will be UPGRADED:
  The following 42 packages will be REMOVED:
  Leave the following dependencies unresolved:

maximum solution count

When an amount of available solutions is big, you may see the following message while resolver is operating:

  W: some solutions were dropped, you may want to increase the value of the 'cupt::resolver::max-solution-count' option

Cupt's native resolver may have only limited amount of different solutions in the memory, and this amount is determined by the value of the cupt::resolver::max-solution-count option. The default value is enough for requests of small and medium complexity, but may be not enough for request of high complexity. So, for systems where there is enough free RAM, consider increasing the value to values like 4000 or even 16000.

Getting debug information

There are several types of debug information available, the debug output is turned on by setting some debug::type option to `yes`. All debug output lines is prepended with D: and are sent to standard error.

resolver

The native resolver will output its resolution tree and scores.

The debug option is debug::resolver.

worker

A debug information regarding scheduling dpkg actions will be printed.

The debug option is debug::worker.

downloader

A debug information regarding downloader's states will be printed.

The debug option is debug::downloader.

gpg signatures

The gpg signature checker will output its debug information.

The debug option is debug::gpgv.

An example: you want to see a very detailed resolver information regarding your query:

  cupt install exim4 -o debug::resolver=yes 2>resolver.debug.log

A debug information will be put to a file resolver.debug.log.