Chapter C. Source packages (from old Packaging Manual)

113

dpkg gencontrol  Pdebian/tmp 

pkg

 p

package

The

 P

tells

dpkg gencontrol

that the package is being built in a non default directory, and

the

 p

tells it which package's control file should be generated.

dpkg gencontrol

also adds information to the list of files in

debian/files

, for the benefit

of (for example) a future invocation of

dpkg genchanges

.

C.1.4

dpkg shlibdeps

  calculates shared library dependencies

This program is usually called from

debian/rules

just before

dpkg gencontrol

(see `The

Debianised source tree' on the following page), in the top level of the source tree.

Its arguments are executables.

2

for which shared library dependencies should be included in

the binary package's control file.

If some of the found shared libraries should only warrant a

Recommends

or

Suggests

, or

if some warrant a

Pre Depends

, this can be achieved by using the

 d

dependency field

option before those executable(s). (Each

 d

option takes effect until the next

 d

.)

dpkg shlibdeps

does not directly cause the output control file to be modified. Instead

by default it adds to the

debian/substvars

file variable settings like

shlibs:Depends

.

These variable settings must be referenced in dependency fields in the appropriate per binary 

package sections of the source control file.

For example, a package that generates an essential part which requires dependencies, and

optional parts that which only require a recommendation, would separate those two sets of

dependencies into two different fields.

3

It can say in its

debian/rules

:

dpkg shlibdeps  dDepends

program anotherprogram ...

\

 dRecommends

optionalpart anotheroptionalpart

and then in its main control file

debian/control

:

...

Depends: ${shlibs:Pre Depends}

Recommends: ${shlibs:Recommends}

...

Sources which produce several binary packages with different shared library dependency re 

quirements can use the

 p

varnameprefix

option to override the default

shlibs:

prefix

(one invocation of

dpkg shlibdeps

per setting of this option). They can thus produce sev 

eral sets of dependency variables, each of the form

varnameprefix

:

dependencyfield

,

which can be referred to in the appropriate parts of the binary package control files.

2

In a forthcoming dpkg version,

dpkg shlibdeps

would be required to be called on shared libraries as well.

They may be specified either in the locations in the source tree where they are created or in the locations in the

temporary build tree where they are installed prior to binary package creation.

3

At the time of writing, an example for this was the

xmms

package, with Depends used for the xmms executable,

Recommends for the plug ins and Suggests for even more optional features provided by unzip.