+ dh $@ --buildsystem=perl_build
+
+Here is an example of overriding where the B<dh_auto_>I<*> commands find
+the package's source, for a package where the source is located in a
+subdirectory.
+
+ #!/usr/bin/make -f
+ %:
+ dh $@ --sourcedirectory=src
+
+And here is an example of how to tell the B<dh_auto_>I<*> commands to build
+in a subdirectory, which will be removed on B<clean>.
+
+ #!/usr/bin/make -f
+ %:
+ dh $@ --builddirectory=build
+
+If your package can be built in parallel, you can support parallel building
+as follows. Then B<dpkg-buildpackage -j> will work.
+
+ #!/usr/bin/make -f
+ %:
+ dh $@ --parallel
+
+Here is a way to prevent B<dh> from running several commands that you don't
+want it to run, by defining empty override targets for each command.
+
+ #!/usr/bin/make -f
+ %:
+ dh $@
+
+ # Commands not to run:
+ override_dh_auto_test override_dh_compress override_dh_fixperms:
+
+A long build process for a separate documentation package can
+be separated out using architecture independent overrides.
+These will be skipped when running build-arch and binary-arch sequences.
+
+ #!/usr/bin/make -f
+ %:
+ dh $@
+
+ override_dh_auto_build-indep:
+ $(MAKE) -C docs
+
+ # No tests needed for docs
+ override_dh_auto_test-indep:
+
+ override_dh_auto_install-indep:
+ $(MAKE) -C docs install
+
+Adding to the example above, suppose you need to chmod a file, but only
+when building the architecture dependent package, as it's not present
+when building only documentation.
+
+ override_dh_fixperms-arch:
+ dh_fixperms
+ chmod 4755 debian/foo/usr/bin/foo
+
+=head1 INTERNALS
+
+If you're curious about B<dh>'s internals, here's how it works under the hood.
+
+Each debhelper command will record when it's successfully run in
+F<debian/package.debhelper.log>. (Which B<dh_clean> deletes.) So B<dh> can tell
+which commands have already been run, for which packages, and skip running
+those commands again.
+
+Each time B<dh> is run, it examines the log, and finds the last logged command
+that is in the specified sequence. It then continues with the next command
+in the sequence. The B<--until>, B<--before>, B<--after>, and B<--remaining>
+options can override this behavior.
+
+A sequence can also run dependent targets in debian/rules. For
+example, the "binary" sequence runs the "install" target.
+
+B<dh> uses the B<DH_INTERNAL_OPTIONS> environment variable to pass information
+through to debhelper commands that are run inside override targets. The
+contents (and indeed, existence) of this environment variable, as the name
+might suggest, is subject to change at any time.
+
+Commands in the B<build-indep>, B<install-indep> and B<binary-indep>
+sequences are passed the B<-i> option to ensure they only work on
+architecture independent packages, and commands in the B<build-arch>,
+B<install-arch> and B<binary-arch> sequences are passed the B<-a>
+option to ensure they only work on architecture dependent packages.
+
+=head1 DEPRECATED OPTIONS
+
+The following options are deprecated. It's much
+better to use override targets instead.
+
+=over 4
+
+=item B<--until> I<cmd>
+
+Run commands in the sequence until and including I<cmd>, then stop.
+
+=item B<--before> I<cmd>
+
+Run commands in the sequence before I<cmd>, then stop.
+
+=item B<--after> I<cmd>
+
+Run commands in the sequence that come after I<cmd>.
+
+=item B<--remaining>
+
+Run all commands in the sequence that have yet to be run.
+
+=back
+
+In the above options, I<cmd> can be a full name of a debhelper command, or
+a substring. It'll first search for a command in the sequence exactly
+matching the name, to avoid any ambiguity. If there are multiple substring
+matches, the last one in the sequence will be used.