halkyon/snap/snapcraft.yaml

# The Linux app as a Snap, built in LXD on a developer's machine, in the repository
# root:
#
#   snapcraft pack
#
# It builds what is committed (the source is this repository's HEAD), never the
# working tree with its build caches, and always for learn.halkyon.eu. Flutter is
# pinned like the local and CI one (FLUTTER_VERSION in .forgejo/workflows/ci.yaml):
# snapcraft's own Flutter plugin can only take a channel and can't pass
# --dart-define, so the build is spelled out below.
name: halkyon-learn
title: Halkyon Learn
base: core24
adopt-info: halkyon-learn # the version, from the app's pubspec.yaml
summary: Learn with flashcards, studied offline and synced between your devices
description: |
  Halkyon Learn is a spaced-repetition app for your own material: studysets of
  flashcards, notes, learning paths and PDFs, reviewed on an FSRS schedule. Every
  studyset is made by its learners: build yours for any subject, or copy one that
  someone published. It works offline and syncs between your devices.

  Learn from what you watch: play films and shows from your Jellyfin server,
  and every subtitle line is split into dictionary words, with readings above
  and the translation below. Tap a word, and it is a flashcard.

  Dictionaries for Japanese, Chinese, Korean, German, Greek and English; kanji,
  hanzi and Hangul written by hand, each stroke checked; exam plans for the
  JLPT, HSK and Korean levels, with a daily pace to your exam's date; and
  studysets published to Explore and copied, later releases coming in as
  merges that keep your own edits.

  It starts with an anonymous account; signing in with GitHub or an email
  address later keeps everything. It connects to learn.halkyon.eu, the project's
  instance, or to any other: everything an instance needs is in the repository,
  to run your own. The app is AGPL-3.0 and the server SSPL-1.0, so all of its
  code is public.

  Questions and reports: support@halkyon.app
license: AGPL-3.0-or-later
source-code: https://code.halkyon.app/project-halkyon/halkyon
# The project's, not an instance's: the app works with any instance.
website: https://halkyon.app/learn
# No contact or issues: the Store refuses an upload whose links aren't http(s) URLs
# ("Links must be http(s):// URLs", checked with snapcraft v9.1.4 on 2026-10-14),
# though snapcraft's reference allows mail addresses there (canonical/snapcraft#6062
# asks for them). Reports come by mail until people can open an account on the issue
# tracker, so the address is in the description.
# The app's icon with rounded corners, made by tool/app_icons.py; also the desktop file's.
icon: snap/gui/halkyon-learn.png
grade: stable
confinement: strict
platforms:
  amd64:

lint:
  ignore:
    # PDFium is loaded by name while the app runs, which the linter can't see.
    - library:
        - bin/lib/libpdfium.so

apps:
  halkyon-learn:
    command: bin/halkyon_learn_flutter
    # How the session is kept: see snap/local/secret-backend.
    command-chain: [bin/secret-backend]
    # GTK, WebKitGTK, GStreamer and libsecret come from the GNOME runtime; files
    # and the browser go through the desktop's portals.
    extensions: [gnome]
    plugs:
      - network
      # GitHub sign-in answers on a loopback address the app listens on.
      - network-bind
      - audio-playback
      # Never connected by itself; whoever connects it by hand gets the keyring.
      - password-manager-service
      # Lets Serverpod hear from NetworkManager that the network went, and end
      # the sync's connection at once rather than after 40 s of silence. Not
      # connected by itself until the Store grants it on a forum request;
      # without it the app logs the refusal once and works on.
      - network-manager-observe

parts:
  flutter:
    plugin: nil
    source: https://github.com/flutter/flutter.git
    source-tag: '3.47.5'
    source-depth: 1
    build-packages:
      - clang
      - cmake
      - curl
      - git
      - libgtk-3-dev
      - lld
      - llvm-18
      - ninja-build
      - pkg-config
      - unzip
      - xz-utils
      - zip
    override-build: |
      mkdir -p "$CRAFT_PART_INSTALL/usr/libexec" "$CRAFT_PART_INSTALL/usr/bin"
      cp -r "$CRAFT_PART_SRC" "$CRAFT_PART_INSTALL/usr/libexec/flutter"
      ln -s ../libexec/flutter/bin/flutter "$CRAFT_PART_INSTALL/usr/bin/flutter"
      ln -s ../libexec/flutter/bin/dart "$CRAFT_PART_INSTALL/usr/bin/dart"
      "$CRAFT_PART_INSTALL/usr/bin/flutter" --disable-analytics
      "$CRAFT_PART_INSTALL/usr/bin/flutter" precache --linux
    # Needed to build, not in the Snap.
    override-prime: ''

  halkyon-learn:
    after: [flutter]
    plugin: nil
    source: .
    source-type: git
    # The sound player links GStreamer, which the GNOME SDK lacks; the GNOME
    # runtime brings the same GStreamer (1.24) to run. The video player
    # (media_kit, for Jellyfin) links libmpv, which neither has: the Snap
    # brings Ubuntu's libmpv2 with what it needs (ffmpeg's libraries), or the
    # app wouldn't start. sodium's build hook compiles libsodium with its
    # configure script and make (ADR 0017), with the clang above.
    build-packages:
      - libgstreamer1.0-dev
      - libgstreamer-plugins-base1.0-dev
      - libmpv-dev
      - make
    stage-packages:
      - libmpv2
    override-build: |
      set -eu
      export PATH="$CRAFT_STAGE/usr/bin:$PATH"
      cd apps/learn/halkyon_learn_flutter
      craftctl set version="$(sed -n 's/^version: *\([^+]*\).*/\1/p' pubspec.yaml)"
      flutter pub get --enforce-lockfile
      flutter build linux --release \
        --dart-define=SERVER_URL=https://learn.halkyon.eu/
      mkdir -p "$CRAFT_PART_INSTALL/bin"
      cp -r build/linux/x64/release/bundle/. "$CRAFT_PART_INSTALL/bin/"
      # ffmpeg's speech recognition (libsphinxbase) links libblas.so.3 and
      # liblapack.so.3, which Ubuntu keeps in blas/ and lapack/ and links into
      # the library folder from its packages' install scripts
      # (update-alternatives), which staging never runs: without these links
      # the app doesn't start. The linter doesn't notice, as the build
      # machine has them.
      lib="$CRAFT_PART_INSTALL/usr/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR"
      mkdir -p "$lib"
      ln -sf blas/libblas.so.3 "$lib/libblas.so.3"
      ln -sf lapack/liblapack.so.3 "$lib/liblapack.so.3"

  secret-backend:
    plugin: dump
    source: snap/local
    organize:
      secret-backend: bin/secret-backend

  # Staged packages bring their whole dependency tree, also what the GNOME
  # runtime and the base hold already: libmpv's ffmpeg brought Ubuntu's older
  # librsvg, cairo, pango, harfbuzz and gdk-pixbuf, which came first on the
  # library path and hid the runtime's newer ones from its GTK (its SVG
  # loader failed for a function only the runtime's librsvg has). So every
  # file the runtime or the base has at the same path goes, as the GNOME
  # extension's reference shows, but only under usr/ and never a directory:
  # its example removes every path the base has, and core24's bin and lib are
  # links, so it would take the app's bin/ with them. blas/ and lapack/ stay:
  # the runtime has them too, but the links into them are the app's own.
  cleanup:
    after: [halkyon-learn, secret-backend]
    plugin: nil
    build-snaps: [core24, gnome-46-2404]
    override-prime: |
      set -eu
      for snap in core24 gnome-46-2404; do
        cd "/snap/$snap/current/usr"
        find . \( -type f -o -type l \) -print0 |
          while IFS= read -r -d '' path; do
            case "$path" in */blas/* | */lapack/*) continue ;; esac
            target="$CRAFT_PRIME/usr/$path"
            if [ -L "$target" ] || [ -f "$target" ]; then
              rm -f "$target"
            fi
          done
      done