+ <refsect1>
+ <title>Periodic and Archives options</title>
+ <para><literal>APT::Periodic</literal> and <literal>APT::Archives</literal>
+ groups of options configure behavior of apt periodic updates, which is
+ done by <literal>/etc/cron.daily/apt</literal> script. See header of
+ this script for the brief documentation of these options.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Debug options</title>
+ <para>
+ Enabling options in the <literal>Debug::</literal> section will
+ cause debugging information to be sent to the standard error
+ stream of the program utilizing the <literal>apt</literal>
+ libraries, or enable special program modes that are primarily
+ useful for debugging the behavior of <literal>apt</literal>.
+ Most of these options are not interesting to a normal user, but a
+ few may be:
+
+ <itemizedlist>
+ <listitem>
+ <para>
+ <literal>Debug::pkgProblemResolver</literal> enables output
+ about the decisions made by
+ <literal>dist-upgrade, upgrade, install, remove, purge</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <literal>Debug::NoLocking</literal> disables all file
+ locking. This can be used to run some operations (for
+ instance, <literal>apt-get -s install</literal>) as a
+ non-root user.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <literal>Debug::pkgDPkgPM</literal> prints out the actual
+ command line each time that <literal>apt</literal> invokes
+ &dpkg;.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <literal>Debug::IdentCdrom</literal> disables the inclusion
+ of statfs data in CDROM IDs. <!-- TODO: provide a
+ motivating example, except I haven't a clue why you'd want
+ to do this. -->
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+
+ <para>
+ A full list of debugging options to apt follows.
+ </para>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>Debug::Acquire::cdrom</literal></term>
+
+ <listitem>
+ <para>
+ Print information related to accessing
+ <literal>cdrom://</literal> sources.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::Acquire::ftp</literal></term>
+
+ <listitem>
+ <para>
+ Print information related to downloading packages using
+ FTP.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::Acquire::http</literal></term>
+
+ <listitem>
+ <para>
+ Print information related to downloading packages using
+ HTTP.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::Acquire::https</literal></term>
+
+ <listitem>
+ <para>
+ Print information related to downloading packages using
+ HTTPS.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::Acquire::gpgv</literal></term>
+
+ <listitem>
+ <para>
+ Print information related to verifying cryptographic
+ signatures using <literal>gpg</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::aptcdrom</literal></term>
+
+ <listitem>
+ <para>
+ Output information about the process of accessing
+ collections of packages stored on CD-ROMs.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::BuildDeps</literal></term>
+ <listitem>
+ <para>
+ Describes the process of resolving build-dependencies in
+ &apt-get;.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::Hashes</literal></term>
+ <listitem>
+ <para>
+ Output each cryptographic hash that is generated by the
+ <literal>apt</literal> libraries.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::IdentCDROM</literal></term>
+ <listitem>
+ <para>
+ Do not include information from <literal>statfs</literal>,
+ namely the number of used and free blocks on the CD-ROM
+ filesystem, when generating an ID for a CD-ROM.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::NoLocking</literal></term>
+ <listitem>
+ <para>
+ Disable all file locking. For instance, this will allow
+ two instances of <quote><literal>apt-get
+ update</literal></quote> to run at the same time.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgAcquire</literal></term>
+
+ <listitem>
+ <para>
+ Log when items are added to or removed from the global
+ download queue.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgAcquire::Auth</literal></term>
+ <listitem>
+ <para>
+ Output status messages and errors related to verifying
+ checksums and cryptographic signatures of downloaded files.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgAcquire::Diffs</literal></term>
+ <listitem>
+ <para>
+ Output information about downloading and applying package
+ index list diffs, and errors relating to package index list
+ diffs.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgAcquire::RRed</literal></term>
+
+ <listitem>
+ <para>
+ Output information related to patching apt package lists
+ when downloading index diffs instead of full indices.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgAcquire::Worker</literal></term>
+
+ <listitem>
+ <para>
+ Log all interactions with the sub-processes that actually
+ perform downloads.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgAutoRemove</literal></term>
+
+ <listitem>
+ <para>
+ Log events related to the automatically-installed status of
+ packages and to the removal of unused packages.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgDepCache::AutoInstall</literal></term>
+ <listitem>
+ <para>
+ Generate debug messages describing which packages are being
+ automatically installed to resolve dependencies. This
+ corresponds to the initial auto-install pass performed in,
+ e.g., <literal>apt-get install</literal>, and not to the
+ full <literal>apt</literal> dependency resolver; see
+ <literal>Debug::pkgProblemResolver</literal> for that.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgDepCache::Marker</literal></term>
+ <listitem>
+ <para>
+ Generate debug messages describing which package is marked
+ as keep/install/remove while the ProblemResolver does his work.
+ Each addition or deletion may trigger additional actions;
+ they are shown indented two additional space under the original entry.
+ The format for each line is <literal>MarkKeep</literal>,
+ <literal>MarkDelete</literal> or <literal>MarkInstall</literal> followed by
+ <literal>package-name <a.b.c -> d.e.f | x.y.z> (section)</literal>
+ where <literal>a.b.c</literal> is the current version of the package,
+ <literal>d.e.f</literal> is the version considered for installation and
+ <literal>x.y.z</literal> is a newer version, but not considered for installation
+ (because of a low pin score). The later two can be omitted if there is none or if
+ it is the same version as the installed.
+ <literal>section</literal> is the name of the section the package appears in.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <!-- Question: why doesn't this do anything? The code says it should. -->
+ <varlistentry>
+ <term><literal>Debug::pkgInitConfig</literal></term>
+ <listitem>
+ <para>
+ Dump the default configuration to standard output on
+ startup.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgDPkgPM</literal></term>
+ <listitem>
+ <para>
+ When invoking &dpkg;, output the precise command line with
+ which it is being invoked, with arguments separated by a
+ single space character.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgDPkgProgressReporting</literal></term>
+ <listitem>
+ <para>
+ Output all the data received from &dpkg; on the status file
+ descriptor and any errors encountered while parsing it.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgOrderList</literal></term>
+
+ <listitem>
+ <para>
+ Generate a trace of the algorithm that decides the order in
+ which <literal>apt</literal> should pass packages to
+ &dpkg;.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgPackageManager</literal></term>
+
+ <listitem>
+ <para>
+ Output status messages tracing the steps performed when
+ invoking &dpkg;.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgPolicy</literal></term>
+
+ <listitem>
+ <para>
+ Output the priority of each package list on startup.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgProblemResolver</literal></term>
+
+ <listitem>
+ <para>
+ Trace the execution of the dependency resolver (this
+ applies only to what happens when a complex dependency
+ problem is encountered).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::pkgProblemResolver::ShowScores</literal></term>
+ <listitem>
+ <para>
+ Display a list of all installed packages with their calculated score
+ used by the pkgProblemResolver. The description of the package
+ is the same as described in <literal>Debug::pkgDepCache::Marker</literal>
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::sourceList</literal></term>
+
+ <listitem>
+ <para>
+ Print information about the vendors read from
+ <filename>/etc/apt/vendors.list</filename>.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>Debug::Vendor</literal></term>
+
+ <listitem>
+ <para>
+ Print information about each vendor.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>