Arch Linux User Repository

If you're encountering errors during the build process, try deleting your Bazel cache (located at ~/.cache/bazel by default).

sudo rm -rf ~/.cache/bazel/*

or

makepkg -osC
cd src/mozc/src
bazel clean --expunge
cd ../../..

sudo pacman -Rs fcitx-qt6 fcitx
makepkg -p PKGBUILD

The development of Fcitx has transitioned to Fcitx5, and Fcitx-Mozc is no longer maintained. Please try the following command.

sudo pacman -Rs fcitx5-qt fcitx5
makepkg -p PKGBUILD.fcitx

I use the following site for build verification and build automation.
If you encounter any issues, please also check here. It may be helpful.
If you are looking for pre-built package files, please check the following GitHub site.
https://github.com/phoepsilonix/mozc-arch/releases

@Muflone

Quite right. I think that's fine too.
So, once Google had reached a milestone, incremented the version number, and incorporated it into fcitx5-Mozc, I created a merge request.
This version also works without issues on my local environment.
I hope it gets reflected eventually.

Naturally, it is possible to update the merge request based on the latest Fcitx5-Mozc commit. Do you think that is necessary?

Arch Linux ships stable packages, except very few exceptions.

so pulling the latest commit in not needed

@Muflone

Thank you for your confirmation.

Regarding the Fcitx5-Mozc package,
the current version of the Fcitx5-Mozc package on Arch Linux is 2.31.5810.102.gb091429.
The latest Mozc version is Mozc-2.32.5981.102+24.11.oss.

https://github.com/fcitx/mozc/commit/29e2b953deacc1b6aa35c28ffedb692399ee4c05
I created the merge request when the Fcitx5-Mozc version number increased. Naturally, it is possible to update the merge request based on the latest Fcitx5-Mozc commit. Do you think that is necessary?
As I cannot receive comments from anyone on GitLab, I am at a loss as to what to do.
I'll take my time and wait for about a month.

confirmed here, the package now builds fine, now I'm closing the pending deletion request. thanks phoepsilonix

about the fcit5-mozc package I know nothing about fcitx but the proposed change doesn't seem to reflect the latest stable release from https://github.com/google/mozc/tags

@fabiscafe

Mr fabiscafe, thank you for your report.
Various issues can arise concerning Rust and Bazel versions and installations. It's also possible that the Rust server might be experiencing temporary difficulties. Some users may even have multiple versions installed to switch between them.
I had intended to accommodate users with TARGETs other than x86_64 for future use, but the core cause this time was likely that it wasn't functioning correctly within the chroot environment.
Thanks to you, fabiscafe, I were able to fix this.
I would also like to express my gratitude once again to the other individuals who submitted reports.

Also, thank you for pointing out the Rust guidelines. I'll check them out later.
Thank you.

PS
I am taking my time waiting for a response to the next merge request. I would be delighted if you could also take things a little more slowly and wait a little longer.
https://gitlab.archlinux.org/archlinux/packaging/packages/fcitx5-mozc/-/merge_requests/8

@phoepsilonix The latest version seems to work for me, thanks!

Essentially what you should try to support is this clean room variant

# Fetch the build-depedencies
pacman -S devtools base-devel git

# git clone the AUR repo
git clone https://aur.archlinux.org/mozc-with-jp-dict.git

# build the package
# this command will setup a build environment and build it against a clean and up-2-date Arch base system
pkgctl build mozc-with-jp-dict

Because everything else is a users own setup, and it would be hard to support them all, especially if it matters how rust was set up or that bazel could conflict. AUR helpers are not supported, so no pressure to support them on your side 😇

There also is this: https://wiki.archlinux.org/title/Rust_package_guidelines that helps a bit

@Muflone @WD_Hiroshi @fabiscafe

Thank you for your report. Since the issue hadn't occurred for a long time, my confirmation was delayed. This PKGBUILD (https://github.com/phoepsilonix/mozc-arch/blob/main/archlinux/PKGBUILD.Dict) builds successfully within an ArchLinux container. The AUR should be equivalent to this, but is the problem occurring persistently? By the way, how are you installing Rust? Using rustup? If it's happening persistently, I'll look into it later. Could you give me a little time?

When building within a chroot environment using the pkgctl command from the devtools package, I have also confirmed in this environment that an error occurs during Rust installation preventing the renaming of LLVM-related files. Furthermore, while Rust offers multiple installation methods, within the chroot environment, the environment variables may not be as expected. Since builds succeed within the ArchLinux container on GitHub, this may be an issue specific to installing Rust within the chroot environment. Therefore, I attempted a fix based on the proposed patch from @fabiscafe.
I would be grateful if you could review it.

@phoepsilonix https://lists.archlinux.org/archives/list/aur-requests@lists.archlinux.org/thread/U6KYLSH3QEXRIU6PLHRDDWRM44E3TCYY

this package doesn't build in a clean chroot. is it for Arch Linux or is broken?

please fix it or the package will be deleted

Hi. This package does not build. It fails with

error: component download failed for llvm-tools-x86_64-unknown-linux-gnu: could not rename downloaded file from '<path>.partial' to '<path>': No such file or directory (os error 2)

link shortend

@phoepsilonix The main issue is that TARGET won't get populated, and I also don't know where cargo/rust home ends up.

I apply the following patch to make it work on my Arch build system.

--- a/PKGBUILD  2025-09-14 21:14:06.037959860 +0200
+++ b/PKGBUILD  2025-09-14 03:58:21.074528414 +0200
@@ -33,7 +33,6 @@
 url="https://github.com/fcitx/mozc"
 license=('Apache-2.0 AND BSD-2-Clause AND BSD-3-Clause AND MIT AND NAIST-2003 AND Unicode-3.0 AND LicenseRef-Okinawa-Dictionary')
 makedepends=('qt6-base' 'fcitx5' 'fcitx5-qt' 'bazel' 'git' 'python' 'mold' 'pkg-config' 'libibus' 'rustup')
-options=(!lto)
 source=("git+$url.git#commit=${_mozc_commit}"
         "bcr::git+https://github.com/bazelbuild/bazel-central-registry.git#commit=${_bcr_commit}"
         "git+https://github.com/abseil/abseil-cpp.git#commit=${_abseil_cpp_commit}"
@@ -84,7 +83,20 @@
   printf "%s.%s.%s.%s" "$MAJOR" "$MINOR" "$BUILD_OSS" "$((REVISION+2))"
 }

+# Use debug
+export CARGO_PROFILE_RELEASE_DEBUG=2 CARGO_PROFILE_RELEASE_STRIP=false
+
+# Use LTO
+export CARGO_PROFILE_RELEASE_LTO=true CARGO_PROFILE_RELEASE_CODEGEN_UNITS=1
+
+# Set default rustup toolchain
+export RUSTUP_TOOLCHAIN=stable
+
 prepare() {
+  # Set rust/cargo home to the build source dir
+  export CARGO_HOME="$srcdir/build/cargo-home"
+  export RUSTUP_HOME="$srcdir/build/rustup-home"
+
   cd "$srcdir/mozc" || exit

   git submodule init
@@ -109,13 +121,12 @@
   # disable warning of ANDROID_NDK_HOME.
   sed -e '/register_toolchains("@androidndk\/\/:all")/d' -i MODULE.bazel

-  rustup update stable
   cd "${srcdir}/dict-to-mozc/" || exit
   #sed -e "s|channel *=.*|channel = \"stable\"|" -i rust-toolchain.toml
   #sed -e "/components.*/d" -i rust-toolchain.toml
   # すだちを優先
   msg '1. Build the rust program(dict-to-mozc), it may take some time...'
-  rustup target list --installed | grep $(rustc -vV | sed -e 's|host: ||' -e 's|-gnu||p' -n) | grep -v musl && TARGET=$(rustup target list --installed | grep $(rustc -vV | sed -e 's|host: ||' -e 's|-gnu||p' -n)|grep -v musl|head -n1) || TARGET=$(rustup target list --installed | grep $(rustc -vV | sed -e 's|host: ||' -e 's|-gnu||p' -n)|grep musl|head -n1)
+  TARGET=$(rustc -vV | sed -n 's/host: //p')
   unset RUSTC
   #CC_=$CC
   #unset CC
@@ -152,6 +163,10 @@
 }

 build() {
+  # Set rust/cargo home to the build source dir
+  export CARGO_HOME="$srcdir/build/cargo-home"
+  export RUSTUP_HOME="$srcdir/build/rustup-home"
+
   cd "$srcdir/mozc/src" || exit

   # Fix compatibility with google-glog 0.3.3 (symbol conflict)
@@ -225,7 +240,6 @@
   install -D -m 644 "$srcdir/LICENSE-SudachiDict" "$pkgdir/usr/share/licenses/$pkgname/data/dictionary_oss/"
   install -D -m 644 "$srcdir/LICENSE-MeCab-unidic-Neologd" "$pkgdir/usr/share/licenses/$pkgname/data/dictionary_oss/"
   install -D -m 644 "$srcdir/LICENSE-MeCab-ipadic-Neologd" "$pkgdir/usr/share/licenses/$pkgname/data/dictionary_oss/"
-
 }

 package_fcitx5-mozc-with-jp-dict() {
@@ -288,4 +302,3 @@
   install -Dm644 unix/emacs/mozc.el                     "$pkgdir/usr/share/emacs/site-lisp/emacs-mozc/mozc.el"
 }

-