Debian packages from Cargo projects

This is a Cargo helper command which automatically creates binary Debian packages (.deb) from Cargo projects.

Installation

rustup update   # Debian's Rust is too outdated, use rustup.rs
cargo install cargo-deb

Requires Rust 1.60+, and optionally dpkg, dpkg-dev and liblzma-dev. Compatible with Ubuntu. If the LZMA dependency causes you headaches, try cargo install cargo-deb --no-default-features.

Usage

cargo deb

Upon running cargo deb from the base directory of your Rust project, the Debian package will be created in target/debian/<project_name>_<version>_<arch>.deb (or you can change the location with the --output option). This package can be installed with dpkg -i target/debian/*.deb.

Debug symbols are stripped from the main binary by default, unless [profile.release] debug = true is set in Cargo.toml. If cargo deb --separate-debug-symbols is run, the debug symbols will be packaged as a separate file installed at /usr/lib/debug/<path-to-binary>.debug.

cargo deb --install builds and installs the project system-wide.

Configuration

No configuration is necessary to make a basic package from a Cargo project with a binary. This command obtains basic information it needs from the Cargo.toml file. It uses Cargo fields: name, version, license, license-file, description, readme, homepage, and repository.

For a more complete Debian package, you may also define a new table, [package.metadata.deb] that contains maintainer, copyright, license-file, changelog, depends, conflicts, breaks, replaces, provides, extended-description/extended-description-file, section, priority, and assets.

For a Debian package that includes one or more systemd unit files you may also wish to define a new (inline) table, [package.metadata.deb.systemd-units], so that the unit files are automatically added as assets and the units are properly installed. Systemd integration

[package.metadata.deb] options

Everything is optional:

• name: The name of the Debian package. If not present, the name of the crate is used.
• maintainer: The person maintaining the Debian packaging. If not present, the first author is used.
• copyright: To whom and when the copyright of the software is granted. If not present, the list of authors is used.
• license-file: 2-element array with a location of the license file and the amount of lines to skip at the top. If not present, package-level license-file is used.
• depends: The runtime dependencies of the project. Generated automatically when absent, or if the list includes the $auto keyword.
• pre-depends: The pre-dependencies of the project. This will be empty by default.
• recommends: The recommended dependencies of the project. This will be empty by default.
• suggests: The suggested dependencies of the project. This will be empty by default.
• enhances: A list of packages this package can enhance. This will be empty by default.
• conflicts, breaks, replaces, provides — package transition control.
• extended-description: An extended description of the project — the more detailed the better. Either extended-description-file (see below) or package's readme file is used if it is not provided.
• extended-description-file: A file with extended description of the project. When specified, used if extended-description is not provided.
• revision: Version of the Debian package (when the package is updated more often than the project).
• section: The application category that the software belongs to.
• priority: Defines if the package is required or optional.
• assets: Files to be included in the package and the permissions to assign them. If assets are not specified, then defaults are taken from binaries listed in [[bin]] (copied to /usr/bin/) and package readme (copied to usr/share/doc/…).
  1. The first argument of each asset is the location of that asset in the Rust project. Glob patterns are allowed. You can use target/release/ in asset paths, even if Cargo is configured to cross-compile or use custom CARGO_TARGET_DIR. The target dir paths will be automatically corrected.
  2. The second argument is where the file will be copied.
     • If is argument ends with / it will be inferred that the target is the directory where the file will be copied.
     • Otherwise, it will be inferred that the source argument will be renamed when copied.
  3. The third argument is the permissions (octal string) to assign that file.
• maintainer-scripts: directory containing templates, preinst, postinst, prerm, or postrm scripts.
• conf-files: List of configuration files that the package management system will not overwrite when the package is upgraded.
• triggers-file: Path to triggers control file for use by the dpkg trigger facility.
• changelog: Path to Debian-formatted changelog file.
• features: List of Cargo features to use when building the package.
• default-features: whether to use default crate features in addition to the features list (default true).
• separate-debug-symbols: whether to keep debug symbols, but strip them from executables and save them in separate files (default false).
• preserve-symlinks: Whether to preserve symlinks in the asset files (default false).
• systemd-units: Optional configuration settings for automated installation of systemd units.

Example of custom Cargo.toml additions

[package.metadata.deb]
maintainer = "Michael Aaron Murphy <mmstickman@gmail.com>"
copyright = "2017, Michael Aaron Murphy <mmstickman@gmail.com>"
license-file = ["LICENSE", "4"]
extended-description = """\
A simple subcommand for the Cargo package manager for \
building Debian packages from Rust projects."""
depends = "$auto"
section = "utility"
priority = "optional"
assets = [
    ["target/release/cargo-deb", "usr/bin/", "755"],
    ["README.md", "usr/share/doc/cargo-deb/README", "644"],
]

Advanced usage

--fast flag uses lighter compression. Useful for very large packages or quick deployment.

[package.metadata.deb.variants.$name]

There can be multiple variants of the metadata in one Cargo.toml file. --variant=name selects the variant to use. Options set in a variant override [package.metadata.deb] options. It automatically adjusts package name.

[package.metadata.deb.systemd-units]

See systemd integration.

Cross-compilation

cargo deb supports a --target flag, which takes Rust target triple. See rustc --print target-list for the list of supported values.

Cross-compilation can be run from any host, including macOS and Windows, provided that Debian-compatible linker and system libraries are available to Rust. The target has to be installed for Rust (e.g. rustup target add i686-unknown-linux-gnu) and has to be installed for the host system (e.g. Debian) (e.g. apt-get install libc6-dev-i386). Note that Rust's and Debian's architecture names are different.

cargo deb --target=i686-unknown-linux-gnu

Cross-compiled archives are saved in target/<target triple>/debian/*.deb. The actual archive path is printed on success.

This option works well for crates that either have no library dependencies or don't want to target an older release. To cross-compile with support for a release older than the host's, consider using a container or a VM.

In .cargo/config you can add [target.<target triple>] strip = { path = "…" } objcopy = { path = "…" } to specify a path to the architecture-specific strip and objcopy commands, or use --no-strip.

Separate debug info

To get debug symbols, set [profile.release] debug = true in Cargo.toml. Building using the dev profile is intentionally unsupported.

cargo deb --separate-debug-symbols

Removes debug symbols from executables and places them as separate files in /usr/lib/debug. Requires GNU objcopy tool.

Custom build flags

If you would like to handle the build process yourself, you can use cargo deb --no-build so that the cargo-deb command will not attempt to rebuild your project.

cargo deb -- <cargo build flags>

Flags after -- are passed to cargo build, so you can use options such as -Z, --frozen, and --locked. Please use that only for features that cargo-deb doesn't support natively.

Workspaces

Cargo-deb understands workspaces and can build all crates in the workspace if necessary. However, you must choose one crate to be the source of the package metadata. You can select which crate to build with -p crate_name or --manifest-path=<path/to/Cargo.toml>.

Custom version strings

cargo deb --deb-version my-custom-version

Overrides the version string generated from the Cargo manifest.