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Elazar Leibovich
Asked: 2016-11-04 12:22:26 +0800 CST

Building dependent deb files

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I'm developing two Ubuntu packages which one depends on the other.

Say, foo which depends on libfoo.

I increment foo and libfoo's version together. It is always the case that foo version 1.2.1 depends on libfoo version 1.2.1.

What's the standard debian process for building libfoo and foo?

Do I have to build and install libfoo before and only then compile foo?

Can I have pbuilder somehow understand foo needs libfoo, and install libfoo before compiling foo?

What's the best practice for this case

package-management

2 Answers

  1. EDIT on extra info in the question:

    Pbuild natively does what you want - just provide it with proper dsc file. Have a look at some real example with version in the dependences like nmap

    apt-get source nmap; cat nmap_*.dsc

    and look at the Build-Depends clause: 

    ...
Build-Depends: debhelper (>= 9), libgtk2.0-dev, dh-autoreconf, flex, bison, libssl-dev, libpcap0.8-dev, libpcre3-dev, binutils-dev, liblinear-dev, python (>= 2.3.5-7), python-all-dev, liblua5.2-dev
...

    In your case you need smth like

    Build-Depends: libfoo (=1.2.1), flex, bison, ...

    Original post:

    So, let us summarise the comments....

    What you need are two clauses from the rule file debian/control:

    • Build-Depends - dependencies of other packages for the source package build
    • Depends - dependencies of other packages for installation package

    I strongly urge you to read the whole Ubuntu Packaging Guide .Your question is addressed at 2.2. The control file . Read also the same information written by Debian team at Debian New Maintainers' Guide, more precisely Chapter 5 - Control files and their fields. The spent time with the manuals will pay off in saving you a lot of troubles in future if you're going to maintain deb packages in your company (or why not in Debian or Ubuntu one day :) ).

    • 2

    • If those packages have separate source archives. I mean they are distinct projects. Then Rostislav Kandilarov's answer is the correct one.

    • Otherwise, If they are in the same source files. Then no worries, if your source compiles & installs well using make (cmake or whatever tool your using). Packaging operation comes after compiling all the source.

    Quick overview of the process after calling debuild...etc (The exact process may override within ./debian/rules file)

    1. Cleans the tree
    2. Compiles it
    3. Installs it to temporary folder ./debian/tmp/

    4. Separate files to ./debian/tmp/foo/ & ./debian/tmp/libfoo/ folders.

      The binary package to be built should be declared in ./debian/control file:

      Source: foo
...

Package: foo
...
Depends: libfoo (=${binary:Version}), ..
...

Package: libfoo
...

      And the files that should be in each package in foo.install & libfoo.install respectively.

    5. Files compressed to debian archives with new generated control files.

    Let me answer your questions:

    • What's the standard debian process for building libfoo and foo?

      :/ I can't recommend those long manual to get start, but just as references To me the best was looking to real examples:

      http://packages.ubuntu.com/source/xenial/vlc

      Do you see how many binary packages are build same source! Check at the bottom and download the *.debian.tar.xz archive which have all files used to package VLC.

    • Do I have to build and install libfoo before and only then compile foo?

      No. no need.

    • Can I have pbuilder somehow understand foo needs libfoo, and install libfoo before compiling foo?

      No. no need in Build-Depends: as it is already available in the source tree. But it needs to be included in Depends: of foo binary.

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