chore(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/rust.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2.3.4
+    - uses: actions/checkout@v6
     - name: Build
       run: cargo build --verbose
     - name: Run tests

CHANGELOG.md

@@ -1,5 +1,74 @@
 # `cargo-aur` Changelog
 
+## Unreleased
+
+#### Added
+
+- A new `custom` field in `[package.metadata.aur]` which accepts a list of
+  strings that will be added as-is to the `package()` function of the PKGBUILD.
+  This allows the user to add specific extra commands to their build process.
+  See the README for more details.
+
+## 1.7.1 (2024-03-18)
+
+#### Fixed
+
+- The crypt startup error `unexpected free argument aur`.
+
+## 1.7.0 (2024-03-07)
+
+#### Added
+
+- The `--output` flag for customizing the location of the output produced by
+  `cargo aur`. If unused, the default remains `target/cargo-aur/`.
+- A new `files` field in `[package.metadata.aur]`, which accepts a list-of-pairs
+  of additional files you want copied to the user's filesystem upon package
+  installation. Output looks like:
+
+```
+package() {
+    install -Dm755 cargo-aur -t "$pkgdir/usr/bin"
+    install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+    install -Dm644 "/path/to/original/foo.txt" "$pkgdir/path/to/target/foo.txt"
+}
+```
+
+#### Fixed
+
+- Supply the `url` from backup sources if `homepage` is not specified in the `Cargo.toml`.
+
+## 1.6.0 (2023-10-02)
+
+#### Changed
+
+- The `[package.metadata]` section for adding extra dependency information
+  should now be named `[package.metadata.aur]`. The old syntax will still work,
+  but you will be warned. This fixes a conflict with other `cargo` subcommands.
+- The PKGBUILD and tarball are now output to `target/cargo-aur/` to avoid
+  cluttering the top-level of the repo.
+- Reduced binary size.
+
+#### Fixed
+
+- LICENSE file checking is now done via SPDX identifiers.
+
+## 1.5.0 (2022-04-20)
+
+#### Added
+
+- Support for `[[bin]]` sections in `Cargo.toml`, allowing you to specify custom
+  binary names separate from the package name. [#13]
+- Support for specifying PKGBUILD `depends` and `optdepends` via
+  `[package.metadata]`, as in:
+
+```toml
+[package.metadata]
+depends = ["nachos", "pizza"]
+optdepends = ["sushi", "ramen"]
+```
+
+[#13]: https://github.com/fosskers/cargo-aur/pull/13
+
 ## 1.4.1 (2021-09-06)
 
 #### Fixed

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "cargo-aur"
-version = "1.4.1"
+version = "1.7.1"
 authors = ["Colin Woodbury <colin@fosskers.ca>"]
-edition = "2018"
+edition = "2021"
 description = "Prepare Rust projects to be released on the Arch Linux User Repository."
 homepage = "https://github.com/fosskers/cargo-aur"
 repository = "https://github.com/fosskers/cargo-aur"
@@ -14,11 +14,18 @@ categories = ["command-line-utilities"]
 [dependencies]
 colored = "2.0"
 gumdrop = "0.8"
-hmac-sha256 = "0.1"
-itertools = "0.10"
-serde = "1.0"
-serde_derive = "1.0"
-toml = "0.5"
+hmac-sha256 = "1.1"
+serde = { version = "1.0", features = ["derive"] }
+toml = "0.8"
 
 [profile.release]
 lto = true
+strip = true
+opt-level = "z"
+codegen-units = 1
+panic = "abort"
+
+[package.metadata.aur]
+# depends = ["blah"]
+# files = [[".github/dependabot.yml", "/usr/local/share/cargo-aur/dependabot.yml"]]
+custom = ["echo hi"]

README.md

@@ -1,27 +1,27 @@
 # cargo-aur
 
-[![Build](https://github.com/fosskers/cargo-aur/workflows/Build/badge.svg)](https://github.com/fosskers/cargo-aur/actions)
-[![](https://img.shields.io/crates/v/cargo-aur.svg)](https://crates.io/crates/cargo-aur)
-![AUR version](https://img.shields.io/aur/version/cargo-aur-bin)
+[![Build](https://github.com/fosskers/cargo-aur/workflows/Build/badge.svg)][3]
+[![](https://img.shields.io/crates/v/cargo-aur.svg)][4]
+![AUR version][5]
 
 `cargo-aur` is a new subcommand for `cargo` that produces a release tarball and
 PKGBUILD file for a Rust project, so that it can be released on the Arch Linux
 User Repository (AUR).
 
 No extra configuration is necessary. As long as your `Cargo.toml` has [the usual
-fields](https://rust-lang.github.io/api-guidelines/documentation.html#c-metadata),
-a PKGBUILD will be generated with all the necessary sections filled out.
+fields][0], a PKGBUILD will be generated with all the necessary sections filled
+out.
 
 ## Installation
 
 Guess what? `cargo-aur` itself is on the AUR! Install it with an AUR-compatible
-package manager like [`aura`](https://github.com/fosskers/aura):
+package manager like [`aura`][1]:
 
 ```
 sudo aura -A cargo-aur-bin
 ```
 
-... or via `cargo`:
+...or via `cargo`:
 
 ```
 cargo install cargo-aur
@@ -29,13 +29,16 @@ cargo install cargo-aur
 
 ## Usage
 
+### Basics
+
 Navigate to a Rust project, and run:
 
 ```
 cargo aur
 ```
 
-This will produce a `foobar-1.2.3-x86_64.tar.gz` tarball and a PKGBUILD.
+This will produce a `foobar-1.2.3-x86_64.tar.gz` tarball and a PKGBUILD within
+`target/cargo-aur`.
 
 If you wish, you can now run `makepkg` to ensure that your package actually builds.
 
@@ -48,6 +51,12 @@ If you wish, you can now run `makepkg` to ensure that your package actually buil
 ==> Finished making: cargo-aur-bin 1.0.0-1 (Wed 10 Jun 2020 08:23:47 PM PDT)
 ```
 
+You can also run `namcap` to verify your package doesn't have errors.
+
+```sh
+> namcap *.zst
+```
+
 Notice that the built package itself is postfixed with `-bin`, which follows the
 AUR standard.
 
@@ -62,10 +71,70 @@ At this point, it is up to you to:
 Some of these steps may be automated in `cargo aur` at a later date if there is
 sufficient demand.
 
+### Custom Binary Names
+
+If you specify a `[[bin]]` section in your `Cargo.toml` and set the `name`
+field, this will be used as the binary name to install within the PKGBUILD.
+
+### `depends` and `optdepends`
+
+If your package requires other Arch packages at runtime, you can specify these
+within your `Cargo.toml` like this:
+
+```toml
+[package.metadata.aur]
+depends = ["nachos", "pizza"]
+optdepends = ["sushi", "ramen"]
+```
+
+And these settings will be copied to your PKGBUILD.
+
+### Including Additional Files
+
+The `files` list can be used to designated initial files to be copied the user's
+filesystem. So this:
+
+```toml
+[package.metadata.aur]
+files = [["path/to/local/foo.txt", "/usr/local/share/your-app/foo.txt"]]
+```
+
+will result in this:
+
+```toml
+package() {
+    install -Dm755 your-app -t "$pkgdir/usr/bin"
+    install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+    install -Dm644 "path/to/local/foo.txt" "$pkgdir/usr/local/share/your-app/foo.txt"
+}
+```
+
+### Custom commands within `package()`
+
+The `custom` list can be used to add specific commands to the `package()`
+function. This config:
+
+```toml
+[package.metadata.aur]
+custom = ["echo hi"]
+```
+
+yields:
+
+```
+package() {
+    install -Dm755 cargo-aur -t "$pkgdir/usr/bin"
+    install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+    echo hi
+}
+```
+
+**Note:** Caveat emptor. No attempt is made to verify the injected commands.
+
 ### Static Binaries
 
 Run with `--musl` to produce a release binary that is statically linked via
-[MUSL](https://musl.libc.org/).
+[MUSL][2].
 
 ```
 > cargo aur --musl
@@ -73,3 +142,10 @@ Run with `--musl` to produce a release binary that is statically linked via
 > ldd <your-binary>
     not a dynamic executable
 ```
+
+[0]: https://rust-lang.github.io/api-guidelines/documentation.html#c-metadata 
+[1]: https://github.com/fosskers/aura
+[2]: https://musl.libc.org/
+[3]: https://github.com/fosskers/cargo-aur/actions
+[4]: https://crates.io/crates/cargo-aur
+[5]: https://img.shields.io/aur/version/cargo-aur-bin

src/error.rs

@@ -1,14 +1,15 @@
 //! Errors that can occur in this application.
 
-use std::fmt::Display;
+use std::{fmt::Display, path::PathBuf};
 
 pub(crate) enum Error {
     IO(std::io::Error),
     Toml(toml::de::Error),
     Utf8(std::str::Utf8Error),
     Utf8OsString,
-    MissingTarget,
+    MissingMuslTarget,
     MissingLicense,
+    TargetNotAbsolute(PathBuf),
 }
 
 impl Display for Error {
@@ -18,13 +19,16 @@ impl Display for Error {
             Error::Toml(e) => write!(f, "{}", e),
             Error::Utf8(e) => write!(f, "{}", e),
             Error::Utf8OsString => write!(f, "The `OsString` was not UTF-8!"),
-            Error::MissingTarget => write!(
+            Error::MissingMuslTarget => write!(
                 f,
                 "Missing target! Try: rustup target add x86_64-unknown-linux-musl"
             ),
             Error::MissingLicense => {
                 write!(f, "Missing LICENSE file. See https://choosealicense.com/")
             }
+            Error::TargetNotAbsolute(p) => {
+                write!(f, "Target filepath is not absolute: {}", p.display())
+            }
         }
     }
 }

src/lib.rs

@@ -0,0 +1,169 @@
+//! Independently testable types and functions.
+
+use serde::Deserialize;
+use std::ops::Not;
+use std::path::{Path, PathBuf};
+
+/// The git forge in which a project's source code is stored.
+pub enum GitHost {
+    Github,
+    Gitlab,
+}
+
+impl GitHost {
+    pub fn source(&self, package: &Package) -> String {
+        match self {
+            GitHost::Github => format!(
+                "{}/releases/download/v$pkgver/{}-$pkgver-x86_64.tar.gz",
+                package.repository, package.name
+            ),
+            GitHost::Gitlab => format!(
+                "{}/-/archive/v$pkgver/{}-$pkgver-x86_64.tar.gz",
+                package.repository, package.name
+            ),
+        }
+    }
+}
+
+/// The critical fields read from a `Cargo.toml` and rewritten into a PKGBUILD.
+#[derive(Deserialize, Debug)]
+pub struct Package {
+    pub name: String,
+    pub version: String,
+    pub authors: Vec<String>,
+    pub description: String,
+    pub repository: String,
+    pub license: String,
+    pub metadata: Option<Metadata>,
+    pub homepage: Option<String>,
+    pub documentation: Option<String>,
+}
+
+impl Package {
+    /// The name of the tarball that should be produced from this `Package`.
+    pub fn tarball(&self, output: &Path) -> PathBuf {
+        output.join(format!("{}-{}-x86_64.tar.gz", self.name, self.version))
+    }
+
+    pub fn git_host(&self) -> Option<GitHost> {
+        if self.repository.starts_with("https://github") {
+            Some(GitHost::Github)
+        } else if self.repository.starts_with("https://gitlab") {
+            Some(GitHost::Gitlab)
+        } else {
+            None
+        }
+    }
+
+    /// Fetch the package URL from its `homepage`, `documentation` or
+    /// `repository` field.
+    pub fn url(&self) -> &str {
+        self.homepage
+            .as_deref()
+            .or(self.documentation.as_deref())
+            .unwrap_or(&self.repository)
+    }
+}
+
+// {
+//     Package {
+//         name: "aura".to_string(),
+//         version: "1.2.3".to_string(),
+//         authors: vec![],
+//         description: "".to_string(),
+//         homepage: "".to_string(),
+//         repository: "".to_string(),
+//         license: "".to_string(),
+//         metadata: None,
+//     }.tarball(Path::new("foobar"))
+// }
+
+/// The `[package.metadata]` TOML block.
+#[derive(Deserialize, Debug)]
+pub struct Metadata {
+    /// Deprecated.
+    #[serde(default)]
+    pub depends: Vec<String>,
+    /// Deprecated.
+    #[serde(default)]
+    pub optdepends: Vec<String>,
+    /// > [package.metadata.aur]
+    pub aur: Option<AUR>,
+}
+
+impl Metadata {
+    /// The metadata block actually has some contents.
+    pub fn non_empty(&self) -> bool {
+        self.depends.is_empty().not()
+            || self.optdepends.is_empty().not()
+            || self
+                .aur
+                .as_ref()
+                .is_some_and(|aur| aur.depends.is_empty().not() || aur.optdepends.is_empty().not())
+    }
+}
+
+impl std::fmt::Display for Metadata {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        // Reconcile which section to read extra dependency information from.
+        // The format we hope the user is using is:
+        //
+        // > [package.metadata.aur]
+        //
+        // But version 1.5 originally supported:
+        //
+        // > [package.metadata]
+        //
+        // To avoid a sudden breakage for users, we support both definition
+        // locations but favour the newer one.
+        //
+        // We print a warning to the user elsewhere if they're still using the
+        // old way.
+        let (deps, opts) = if let Some(aur) = self.aur.as_ref() {
+            (aur.depends.as_slice(), aur.optdepends.as_slice())
+        } else {
+            (self.depends.as_slice(), self.optdepends.as_slice())
+        };
+
+        match deps {
+            [middle @ .., last] => {
+                write!(f, "depends=(")?;
+                for item in middle {
+                    write!(f, "\"{}\" ", item)?;
+                }
+                if opts.is_empty().not() {
+                    writeln!(f, "\"{}\")", last)?;
+                } else {
+                    write!(f, "\"{}\")", last)?;
+                }
+            }
+            [] => {}
+        }
+
+        match opts {
+            [middle @ .., last] => {
+                write!(f, "optdepends=(")?;
+                for item in middle {
+                    write!(f, "\"{}\" ", item)?;
+                }
+                write!(f, "\"{}\")", last)?;
+            }
+            [] => {}
+        }
+
+        Ok(())
+    }
+}
+
+/// The inner values of a `[package.metadata.aur]` TOML block.
+#[derive(Deserialize, Debug)]
+pub struct AUR {
+    #[serde(default)]
+    depends: Vec<String>,
+    #[serde(default)]
+    optdepends: Vec<String>,
+    #[serde(default)]
+    pub files: Vec<(PathBuf, PathBuf)>,
+    #[serde(default)]
+    pub custom: Vec<String>,
+}

src/main.rs

@@ -1,106 +1,90 @@
-pub(crate) mod error;
+mod error;
 
 use crate::error::Error;
+use cargo_aur::{GitHost, Package};
 use colored::*;
 use gumdrop::{Options, ParsingStyle};
 use hmac_sha256::Hash;
-use itertools::Itertools;
-use serde_derive::Deserialize;
-use std::ffi::OsString;
+use serde::Deserialize;
 use std::fs::{DirEntry, File};
 use std::io::{BufWriter, Write};
 use std::ops::Not;
 use std::path::{Path, PathBuf};
-use std::process::Command;
+use std::process::{Command, ExitCode};
 
-/// Licenses avaiable from the Arch Linux `licenses` package.
+/// Licenses available from the Arch Linux `licenses` package.
 ///
 /// That package contains other licenses, but I've excluded here those unlikely
 /// to be used by Rust crates.
 const LICENSES: &[&str] = &[
-    "AGPL3", "APACHE", "GPL2", "GPL3", "LGPL2.1", "LGPL3", "MPL", "MPL2",
+    "AGPL-3.0-only",
+    "AGPL-3.0-or-later",
+    "Apache-2.0",
+    "BSL-1.0", // Boost Software License.
+    "GPL-2.0-only",
+    "GPL-2.0-or-later",
+    "GPL-3.0-only",
+    "GPL-3.0-or-later",
+    "LGPL-2.0-only",
+    "LGPL-2.0-or-later",
+    "LGPL-3.0-only",
+    "LGPL-3.0-or-later",
+    "MPL-2.0",   // Mozilla Public License.
+    "Unlicense", // Not to be confused with "Unlicensed".
 ];
 
 #[derive(Options)]
 struct Args {
     /// Display this help message.
     help: bool,
-
     /// Display the current version of this software.
     version: bool,
-
-    /// Unused.
-    #[options(free)]
-    args: Vec<String>,
-
+    /// Set a custom output directory (default: target/).
+    output: Option<PathBuf>,
     /// Use the MUSL build target to produce a static binary.
     musl: bool,
-}
-
-enum GitHost {
-    Github,
-    Gitlab,
-}
-
-impl GitHost {
-    fn source(&self, package: &Package) -> String {
-        match self {
-            GitHost::Github => format!(
-                "{}/releases/download/v$pkgver/{}-$pkgver-x86_64.tar.gz",
-                package.repository, package.name
-            ),
-            GitHost::Gitlab => format!(
-                "{}/-/archive/v$pkgver/{}-$pkgver-x86_64.tar.gz",
-                package.repository, package.name
-            ),
-        }
-    }
+    /// Don't actually build anything.
+    dryrun: bool,
+    /// Absorbs any extra junk arguments.
+    #[options(free)]
+    free: Vec<String>,
 }
 
 #[derive(Deserialize, Debug)]
 struct Config {
     package: Package,
+    #[serde(default)]
+    bin: Vec<Binary>,
+}
+
+impl Config {
+    /// The name of the compiled binary that should be copied to the tarball.
+    fn binary_name(&self) -> &str {
+        self.bin
+            .first()
+            .map(|bin| bin.name.as_str())
+            .unwrap_or(self.package.name.as_str())
+    }
 }
 
 #[derive(Deserialize, Debug)]
-struct Package {
+struct Binary {
     name: String,
-    version: String,
-    authors: Vec<String>,
-    description: String,
-    homepage: String,
-    repository: String,
-    license: String,
 }
 
-impl Package {
-    /// The name of the tarball that should be produced from this `Package`.
-    fn tarball(&self) -> String {
-        format!("{}-{}-x86_64.tar.gz", self.name, self.version)
-    }
-
-    fn git_host(&self) -> Option<GitHost> {
-        if self.repository.starts_with("https://github") {
-            Some(GitHost::Github)
-        } else if self.repository.starts_with("https://gitlab") {
-            Some(GitHost::Gitlab)
-        } else {
-            None
-        }
-    }
-}
-
-fn main() {
+fn main() -> ExitCode {
     let args = Args::parse_args_or_exit(ParsingStyle::AllOptions);
 
     if args.version {
         let version = env!("CARGO_PKG_VERSION");
         println!("{}", version);
+        ExitCode::SUCCESS
     } else if let Err(e) = work(args) {
         eprintln!("{} {}: {}", "::".bold(), "Error".bold().red(), e);
-        std::process::exit(1)
+        ExitCode::FAILURE
     } else {
         println!("{} {}", "::".bold(), "Done.".bold().green());
+        ExitCode::SUCCESS
     }
 }
 
@@ -112,33 +96,64 @@ fn work(args: Args) -> Result<(), Error> {
         musl_check()?
     }
 
-    let package = cargo_config()?;
-    let license = if must_copy_license(&package.license) {
+    // Where cargo expects to read and write to. By default we want to read the
+    // built binary from `target/release` and we want to write our results to
+    // `target/cargo-aur`, but these are configurable by the user.
+    let cargo_target: PathBuf = match std::env::var_os("CARGO_TARGET_DIR") {
+        Some(p) => PathBuf::from(p),
+        None => PathBuf::from("target"),
+    };
+
+    let output = args.output.unwrap_or(cargo_target.join("cargo-aur"));
+
+    // Ensure the target can actually be written to. Otherwise the `tar`
+    // operation later on will fail.
+    std::fs::create_dir_all(&output)?;
+
+    let config = cargo_config()?;
+
+    // Warn if the user if still using the old metadata definition style.
+    if let Some(metadata) = config.package.metadata.as_ref() {
+        if metadata.depends.is_empty().not() || metadata.optdepends.is_empty().not() {
+            p("Use of [package.metadata] is deprecated. Please specify extra dependencies under [package.metadata.aur].".bold().yellow());
+        }
+    }
+
+    let license = if must_copy_license(&config.package.license) {
         p("LICENSE file will be installed manually.".bold().yellow());
         Some(license_file()?)
     } else {
         None
     };
-    release_build(args.musl)?;
-    tarball(args.musl, license.as_ref(), &package)?;
-    let sha256: String = sha256sum(&package)?;
 
-    // Write the PKGBUILD.
-    let file = BufWriter::new(File::create("PKGBUILD")?);
-    pkgbuild(file, &package, &sha256, license.as_ref())?;
+    if args.dryrun.not() {
+        release_build(args.musl)?;
+        tarball(args.musl, &cargo_target, &output, license.as_ref(), &config)?;
+        let sha256: String = sha256sum(&config.package, &output)?;
+
+        // Write the PKGBUILD.
+        let path = output.join("PKGBUILD");
+        let file = BufWriter::new(File::create(path)?);
+        pkgbuild(file, &config, &sha256, license.as_ref())?;
+    }
 
     Ok(())
 }
 
-fn cargo_config() -> Result<Package, Error> {
+/// Read the `Cargo.toml` for all the fields of concern to this tool.
+fn cargo_config() -> Result<Config, Error> {
+    // NOTE 2023-11-27 Yes it looks silly to be reading the whole thing into a
+    // string here, but the `toml` library doesn't allow deserialization from
+    // anything else but a string.
     let content = std::fs::read_to_string("Cargo.toml")?;
     let proj: Config = toml::from_str(&content)?;
-    Ok(proj.package)
+    Ok(proj)
 }
 
 /// If a AUR package's license isn't included in `/usr/share/licenses/common/`,
-/// then it must be installed manually by the PKGBUILD. MIT is such a missing
-/// license, and since many Rust crates use MIT we must make this check.
+/// then it must be installed manually by the PKGBUILD. MIT and BSD3 are such
+/// missing licenses, and since many Rust crates use them we must make this
+/// check.
 fn must_copy_license(license: &str) -> bool {
     LICENSES.contains(&license).not()
 }
@@ -158,21 +173,26 @@ fn license_file() -> Result<DirEntry, Error> {
 }
 
 /// Write a legal PKGBUILD to some `Write` instance (a `File` in this case).
-fn pkgbuild<T: Write>(
+fn pkgbuild<T>(
     mut file: T,
-    package: &Package,
+    config: &Config,
     sha256: &str,
     license: Option<&DirEntry>,
-) -> Result<(), Error> {
+) -> Result<(), Error>
+where
+    T: Write,
+{
+    let package = &config.package;
     let authors = package
         .authors
         .iter()
         .map(|a| format!("# Maintainer: {}", a))
+        .collect::<Vec<_>>()
         .join("\n");
     let source = package
         .git_host()
         .unwrap_or(GitHost::Github)
-        .source(package);
+        .source(&config.package);
 
     writeln!(file, "{}", authors)?;
     writeln!(file, "#")?;
@@ -185,11 +205,19 @@ fn pkgbuild<T: Write>(
     writeln!(file, "pkgver={}", package.version)?;
     writeln!(file, "pkgrel=1")?;
     writeln!(file, "pkgdesc=\"{}\"", package.description)?;
-    writeln!(file, "url=\"{}\"", package.homepage)?;
+    writeln!(file, "url=\"{}\"", package.url())?;
     writeln!(file, "license=(\"{}\")", package.license)?;
     writeln!(file, "arch=(\"x86_64\")")?;
     writeln!(file, "provides=(\"{}\")", package.name)?;
     writeln!(file, "conflicts=(\"{}\")", package.name)?;
+
+    match package.metadata.as_ref() {
+        Some(metadata) if metadata.non_empty() => {
+            writeln!(file, "{}", metadata)?;
+        }
+        Some(_) | None => {}
+    }
+
     writeln!(file, "source=(\"{}\")", source)?;
     writeln!(file, "sha256sums=(\"{}\")", sha256)?;
     writeln!(file)?;
@@ -197,7 +225,7 @@ fn pkgbuild<T: Write>(
     writeln!(
         file,
         "    install -Dm755 {} -t \"$pkgdir/usr/bin\"",
-        package.name
+        config.binary_name()
     )?;
 
     if let Some(lic) = license {
@@ -212,6 +240,25 @@ fn pkgbuild<T: Write>(
         )?;
     }
 
+    if let Some(aur) = package.metadata.as_ref().and_then(|m| m.aur.as_ref()) {
+        for (source, target) in aur.files.iter() {
+            if target.has_root().not() {
+                return Err(Error::TargetNotAbsolute(target.to_path_buf()));
+            } else {
+                writeln!(
+                    file,
+                    "    install -Dm644 \"{}\" \"$pkgdir{}\"",
+                    source.display(),
+                    target.display()
+                )?;
+            }
+        }
+
+        for custom in aur.custom.iter() {
+            writeln!(file, "    {}", custom)?;
+        }
+    }
+
     writeln!(file, "}}")?;
     Ok(())
 }
@@ -229,35 +276,49 @@ fn release_build(musl: bool) -> Result<(), Error> {
     Ok(())
 }
 
-fn tarball(musl: bool, license: Option<&DirEntry>, package: &Package) -> Result<(), Error> {
-    let target_dir: OsString = match std::env::var_os("CARGO_TARGET_DIR") {
-        Some(p) => p,
-        None => "target".into(),
-    };
-
+fn tarball(
+    musl: bool,
+    cargo_target: &Path,
+    output: &Path,
+    license: Option<&DirEntry>,
+    config: &Config,
+) -> Result<(), Error> {
     let release_dir = if musl {
         "x86_64-unknown-linux-musl/release"
     } else {
         "release"
     };
 
-    let mut binary: PathBuf = target_dir.into();
-    binary.push(release_dir);
-    binary.push(&package.name);
+    let binary_name = config.binary_name();
+    let binary = cargo_target.join(release_dir).join(binary_name);
 
     strip(&binary)?;
-    std::fs::copy(binary, &package.name)?;
+    std::fs::copy(binary, binary_name)?;
 
     // Create the tarball.
     p("Packing tarball...".bold());
     let mut command = Command::new("tar");
-    command.arg("czf").arg(package.tarball()).arg(&package.name);
+    command
+        .arg("czf")
+        .arg(config.package.tarball(output))
+        .arg(binary_name);
     if let Some(lic) = license {
         command.arg(lic.path());
     }
+    if let Some(files) = config
+        .package
+        .metadata
+        .as_ref()
+        .and_then(|m| m.aur.as_ref())
+        .map(|a| a.files.as_slice())
+    {
+        for (file, _) in files {
+            command.arg(file);
+        }
+    }
     command.status()?;
 
-    std::fs::remove_file(&package.name)?;
+    std::fs::remove_file(binary_name)?;
 
     Ok(())
 }
@@ -270,8 +331,8 @@ fn strip(path: &Path) -> Result<(), Error> {
     Ok(()) // FIXME Would love to use my `void` package here and elsewhere.
 }
 
-fn sha256sum(package: &Package) -> Result<String, Error> {
-    let bytes = std::fs::read(package.tarball())?;
+fn sha256sum(package: &Package, output: &Path) -> Result<String, Error> {
+    let bytes = std::fs::read(package.tarball(output))?;
     let digest = Hash::hash(&bytes);
     let hex = digest.iter().map(|u| format!("{:02x}", u)).collect();
     Ok(hex)
@@ -279,17 +340,14 @@ fn sha256sum(package: &Package) -> Result<String, Error> {
 
 /// Does the user have the `x86_64-unknown-linux-musl` target installed?
 fn musl_check() -> Result<(), Error> {
-    let args = vec!["target", "list", "--installed"];
+    let args = ["target", "list", "--installed"];
     let output = Command::new("rustup").args(args).output()?.stdout;
-    let installed = std::str::from_utf8(&output)?
-        .lines()
-        .any(|tc| tc == "x86_64-unknown-linux-musl");
 
-    if installed {
-        Ok(())
-    } else {
-        Err(Error::MissingTarget)
-    }
+    std::str::from_utf8(&output)?
+        .lines()
+        .any(|tc| tc == "x86_64-unknown-linux-musl")
+        .then_some(())
+        .ok_or(Error::MissingMuslTarget)
 }
 
 fn p(msg: ColoredString) {