Build Debian packages in Launchpad

The easiest way to build a Debian (.deb) package is to let Launchpad do it for you. You build a source package on your own machine, sign it, and upload it to a Personal Package Archive (PPA). Launchpad then compiles the binary packages for each declared architecture using the same builders as the official Ubuntu archive, and publishes them so anyone can install them.

Building this way means you don’t have to run your own build infrastructure, and the resulting packages are publicly available which is handy for sharing test builds with bug reporters or reviewers.

Note

Launchpad builds packages from source and does not accept pre-built .deb files. You only upload a source package (a .dsc and its related files).

Prerequisites

Before you start, make sure you have:

  • An OpenPGP key registered on your account. Launchpad only accepts uploads signed by a key it knows. Add your key at https://launchpad.net/~/+editpgpkeys.

  • A PPA to upload to. If you don’t have one yet, see Create a Personal Package Archive (PPA).

  • The packaging tools installed. You will need these to edit the changelog, build the source package, sign the upload with your GPG key, and upload it:

    sudo apt install devscripts dpkg-dev dput

Set your packaging identity

Package tools stamp each changelog entry with an author name and email. Set these to match the identity of the key registered on your Launchpad account, so the changelog and the signature agree:

export DEBFULLNAME="Your Name"
export DEBEMAIL="you@example.com"

Get the package source

Fetch the source of the package you want to build. For an existing Ubuntu package:

apt-get source <package>
cd <package>-*/

If you are packaging your own software, start from your existing source tree containing a debian/ directory.

Note

If your goal is to contribute to Ubuntu packages, it is recommended to use git-ubuntu instead of apt-get to get the source code.

Set a PPA-specific version

A PPA won’t accept a version string that is lower or equal to the one already in the archive, and it won’t accept the same version twice. If you want to distribute or use your software from the PPA, it is recommended that you add a suffix to the version in debian/changelog so it is unique to your PPA.

The tilde (~) character sorts lower than everything else, so appending ~<label>1 keeps your PPA version just below the official one – which is what you want for a rebuild. Use dch to add the entry, naming the Ubuntu release you are targeting as both the suffix and the distribution:

codename="noble"
dch -l "~${codename}" --distribution "${codename}" "Build for PPA"

For example, this turns hello (2.10-5build1) into hello (2.10-5build1~noble1). Set codename to the release you are building for (for example noble for 24.04, jammy for 22.04).

Important

Include a number at the end of the suffix (~noble1, ~noble2, …). Once Launchpad accepts an upload, it will not accept another upload with the same or a lower version. If you need to fix anything and re-upload, increment the number.

Using the release codename in the suffix is optional, but it makes each version unique per release and shows users which package matches which Ubuntu release. This is useful if you later build the same fix for several releases. See the Ubuntu project docs for more details on versioning.

Build the signed source package

After setting the version, you need to build a source-only package. dpkg-buildpackage reads the version from the top of debian/changelog and produces the .dsc, .debian.tar.*, .buildinfo, and .changes files in the parent directory:

dpkg-buildpackage -S -I -i -nc -d

  • -S builds a source package.

  • -I and -i exclude version-control and backup files.

  • -nc skips cleaning so the tree is left as-is.

  • -d skips the build-dependency check, which isn’t needed for a source build.

If a signing key is available, this step also signs the files.

You may see a warning that the new version is “earlier than the previous one”. This is expected for a PPA rebuild because of versioning rules that ensure if the package in the official archive is updated, it will be chosen over yours. See this section on comparing versions for more details.

Sign the source package

The upload must be signed by the key registered on your Launchpad account. If dpkg-buildpackage did not sign the files (for example, because no key was available at build time), sign them explicitly with debsign, naming the key to be sure the right one is used:

debsign -k <your-key-id> ../<package>_<version>_source.changes

Find your key ID with:

gpg --list-secret-keys --keyid-format long

debsign signs the .dsc, .buildinfo, and .changes files. You will be prompted for your key passphrase.

Upload to your PPA

Upload the .changes file with dput. dput reads it and uploads the referenced .dsc and source tarball to Launchpad:

dput ppa:<username>/<ppa-name> ../<package>_<version>_source.changes

For the hello example targeting the personal PPA:

dput ppa:<username>/personal ../hello_2.10-5build1~noble1_source.changes

For more upload options (SFTP, custom dput targets, team PPAs), see Upload a package to a PPA.

Watch the build

You must wait for Launchpad to build the package server-side before you can install from the PPA. This can take anywhere from a few minutes to a few hours, depending on how busy the build farm is.

Launchpad will send you an Accepted or Rejected notice via email once it checks the signature and version, then sends build-status mails per architecture. You can also watch progress on the PPA’s package page:

https://launchpad.net/~<your-lp-id>/+archive/ubuntu/<ppa-name>/+packages

If the source package was not signed, no email will be sent because Launchpad has no way of verifying the uploader.

Launchpad first builds the binaries for each enabled architecture, then publishes the source and binary packages for public download.

Note

A PPA keeps only one version of a given source package per Ubuntu series – the highest one. Uploading a newer version supersedes the previous one (the old version stays visible in the publishing history). Uploading the same or a lower version is rejected.

Next steps