i18n POC #680

Code7R · 2026-01-01T17:26:52Z

Basic example of POC intergration into a Rust project. Some bits are still missing:

translation of clap/derive handled strings (i.e. --help output is not translated yet, this will be the next goal)
proper installation of the MO files into target location (cargo-install does NOT transfer them)
document on where to get a capable version of gettext (Debian/Ubuntu do not have them, for example)
further digging and marking of more strings which are worth translating

Experimental German translation Simplify i18n usage with i18n_format

Copilot

Pull request overview

This PR introduces a proof-of-concept for internationalization (i18n) support using the gettext framework. It wraps user-facing strings in the Rust codebase with i18n_format! macros and adds the necessary infrastructure for translation management.

Adds gettext-based i18n infrastructure with German translations as a proof of concept
Wraps error messages and log output in translation macros
Creates build system support for compiling .po translation files to .mo format

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
xpo.sh	Shell script for extracting and updating translation files from source code
po/encfs.pot	Translation template with extracted translatable strings
po/de.po	German translation file with 775 lines including legacy translations
po/LINGUAS	List of supported languages (currently only German)
build.rs	Build script that compiles .po files to .mo format using msgfmt
src/main.rs	Initializes i18n and wraps user-facing strings in translation macros
src/lib.rs	Implements i18n module with gettext integration and feature flag support
src/fs.rs	Wraps filesystem error messages with translation macros
src/crypto/file.rs	Wraps decryption error messages with translation macros
Cargo.toml	Adds gettext-rs and i18n-format dependencies with gettext feature flag
README.md	Documents i18n support and gettext version requirements
INSTALL.md	Adds documentation for disabling i18n and customizing locale directory
.gitignore	Ignores editor temporary files (vim swap files)

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Copilot · 2026-01-01T20:30:07Z

README.md

+For i18n, the script xpo.sh may be used to update translations from time to
+time. For translation string contribution, see the management service hosted by
+Canonical [Launchpad](https://launchpad.net/encfs). NOTE: frozen versions of
+gettext utilities in Linux distributions may lack Rust langugate support.


There's a typo in the word "langugate" which should be "language".

Suggested change

gettext utilities in Linux distributions may lack Rust langugate support.

gettext utilities in Linux distributions may lack Rust language support.

Copilot · 2026-01-01T20:30:07Z

src/lib.rs

+        let locale_dir = concat!(env!("OUT_DIR"), "/po");
+        // actually make it customizable at build time
+        let locale_dir = option_env!("ENCFS_LOCALE_DIR").unwrap_or(locale_dir);


The runtime code uses option_env!("ENCFS_LOCALE_DIR") to read an environment variable at compile time, but this won't read the value that was set using cargo:rustc-env=ENCFS_LOCALE_DIR in build.rs (line 21). The cargo:rustc-env directive sets a compile-time environment variable that should be read with env!() instead. The current implementation will always use the hardcoded fallback path and ignore the value set by build.rs.

Suggested change

let locale_dir = concat!(env!("OUT_DIR"), "/po");

// actually make it customizable at build time

let locale_dir = option_env!("ENCFS_LOCALE_DIR").unwrap_or(locale_dir);

// Use the locale directory provided at build time via `cargo:rustc-env=ENCFS_LOCALE_DIR`

let locale_dir = env!("ENCFS_LOCALE_DIR");

Copilot · 2026-01-01T20:30:07Z

Cargo.toml

+gettext-rs = { version = "0.7.7", features = ["gettext-system"] }
+i18n-format = "0.4.0"


The gettext feature is defined but doesn't enable the required dependencies. The gettext-rs and i18n-format dependencies should be marked as optional and only enabled when the gettext feature is active. Currently, these dependencies are always included even when building with --no-default-features, which contradicts the stated goal in INSTALL.md of being able to disable i18n support.

Copilot · 2026-01-01T20:30:07Z

src/fs.rs

                    let (encrypted_name, new_iv) =
                        self.cipher.encrypt_filename(name_bytes, iv).map_err(|e| {
-                            error!("Encrypt filename failed: {}", e);
+                            error!("{}", i18n_format!("Encrypt filename failed: {}", e)); //.unwrap()); //  formatx!(gettext("Encrypt filename failed: {}"), e).unwrap());


There's an unnecessary commented-out code fragment ".unwrap()); // formatx!(gettext(...".unwrap());" at the end of the line. This should be removed to keep the code clean.

Suggested change

error!("{}", i18n_format!("Encrypt filename failed: {}", e)); //.unwrap()); // formatx!(gettext("Encrypt filename failed: {}"), e).unwrap());

error!("{}", i18n_format!("Encrypt filename failed: {}", e));

Copilot · 2026-01-01T20:30:08Z

build.rs

+        .arg(mo_path)
+        .arg("--statistics")
+        .status()
+        .expect("failed to execute msgfmt");


The error handling here uses .expect() with a generic message. If the msgfmt command is not found in the PATH, this will produce a confusing error. Consider providing a more helpful error message that suggests installing gettext tools or checking the PATH.

Suggested change

.expect("failed to execute msgfmt");

.unwrap_or_else(|e| {

panic!(

"failed to execute `msgfmt`: {}. Ensure GNU gettext tools are installed and that `msgfmt` is available in your PATH.",

e

);

});

Copilot · 2026-01-01T20:30:08Z

src/lib.rs


+#[cfg(feature = "gettext")]
+///
+/// Helper class to handle i18n-specific helper functions, or dummies wrappers to disable


The documentation comment uses "Helper class" which is not the appropriate Rust terminology. In Rust, this should be referred to as a "module" since it's defined with pub mod i18n. The comment should read "Helper module to handle i18n-specific helper functions..."

Suggested change

/// Helper class to handle i18n-specific helper functions, or dummies wrappers to disable

/// Helper module to handle i18n-specific helper functions, or dummies wrappers to disable

Copilot · 2026-01-01T20:30:08Z

build.rs

+
+    let locale_dir = env::var("ENCFS_LOCALE_DIR")
+        .map(PathBuf::from)
+        .unwrap_or_else(|_| PathBuf::from(env::var("OUT_DIR").unwrap()).join("i18n"));


The build script constructs a default locale_dir path using "i18n" as the subdirectory name, but when no ENCFS_LOCALE_DIR environment variable is set, this results in OUT_DIR/i18n being used. However, in src/lib.rs line 16, the default path uses OUT_DIR/po. This inconsistency could lead to runtime errors where the compiled .mo files are in one location but the code looks for them in another.

Suggested change

.unwrap_or_else(|_| PathBuf::from(env::var("OUT_DIR").unwrap()).join("i18n"));

.unwrap_or_else(|_| PathBuf::from(env::var("OUT_DIR").unwrap()).join("po"));

Copilot · 2026-01-01T20:30:09Z

xpo.sh

+#!/bin/sh -e
+
+pot=po/encfs.pot
+langs=`grep -v '#' po/LINGUAS`


The script uses backticks for command substitution which is the older sh/bash syntax. While this works, the more modern and preferred syntax is $() instead of backticks. Consider changing langs=grep -v '#' po/LINGUAS`` to langs=$(grep -v '#' po/LINGUAS) for better readability and nesting support.

Suggested change

langs=`grep -v '#' po/LINGUAS`

langs=$(grep -v '#' po/LINGUAS)

Copilot · 2026-01-01T20:30:09Z

build.rs

+fn main() {
+    // Skip compilation when using system gettext
+    if env::var_os("CARGO_FEATURE_GETTEXT_SYSTEM").is_some() {
+        println!("cargo:warning=Using system gettext translations");
+        return;
+    }


The build.rs script will always attempt to compile translations and execute msgfmt, even when building with --no-default-features to disable i18n support. The script should check for the gettext feature and skip translation compilation when the feature is disabled. Consider adding a feature check at the beginning: if env::var_os("CARGO_FEATURE_GETTEXT").is_none() { return; }

Added POC of i18n integration

37db6d2

Experimental German translation Simplify i18n usage with i18n_format

vgough requested a review from Copilot January 1, 2026 20:25

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vgough mentioned this pull request Jan 2, 2026

another attempt at i18n support #681

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i18n POC #680

i18n POC #680

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	gettext utilities in Linux distributions may lack Rust langugate support.
	gettext utilities in Linux distributions may lack Rust language support.

		gettext-rs = { version = "0.7.7", features = ["gettext-system"] }
		i18n-format = "0.4.0"

	error!("{}", i18n_format!("Encrypt filename failed: {}", e)); //.unwrap()); // formatx!(gettext("Encrypt filename failed: {}"), e).unwrap());
	error!("{}", i18n_format!("Encrypt filename failed: {}", e));

-        .expect("failed to execute msgfmt");
+        .unwrap_or_else(|e| {
+            panic!(
+                "failed to execute `msgfmt`: {}. Ensure GNU gettext tools are installed and that `msgfmt` is available in your PATH.",
+                e
+            );
+        });

	/// Helper class to handle i18n-specific helper functions, or dummies wrappers to disable
	/// Helper module to handle i18n-specific helper functions, or dummies wrappers to disable

	.unwrap_or_else(\|_\| PathBuf::from(env::var("OUT_DIR").unwrap()).join("i18n"));
	.unwrap_or_else(\|_\| PathBuf::from(env::var("OUT_DIR").unwrap()).join("po"));

	langs=`grep -v '#' po/LINGUAS`
	langs=$(grep -v '#' po/LINGUAS)

i18n POC #680

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