Flutter Termux Installer

This repo installs a full Flutter SDK checkout for Termux-style Android shells and overlays it with Android-bionic host tools built from the Flutter engine.

It pulls the host bundle from:

• https://github.com/sirvkrm/flutter-android-bionic-builder

It pulls Android-bionic Dart SDK mirror zips from:

• https://github.com/sirvkrm/dart-android-bionic-builder

The host bundle provides the pieces the stock Flutter SDK does not ship for Android-hosted terminals:

• bin/cache/dart-sdk built for Android bionic host arch (arm64 or x64)
• bin/cache/artifacts/engine/linux-<host-arch>/font-subset
• bin/cache/artifacts/engine/linux-<host-arch>/const_finder.dart.snapshot
• bin/cache/artifacts/engine/android-*-{profile,release}/android-<host-arch>/gen_snapshot

The installer patches flutter_tools so Android-hosted Termux uses the android-<host-arch> Android snapshot tool cache namespace instead of linux-x64. It also sets FLUTTER_TERMUX_ARTIFACT_BASE_URL in env.sh, so Android-host snapshot zips can be fetched from this project's GitHub releases if missing. It also sets FLUTTER_TERMUX_DART_ARTIFACT_BASE_URL in env.sh, so Android hosts fetch Dart SDK zips from the Dart mirror repo (same release tag as the installed host bundle) instead of Flutter's Google-hosted Linux Dart zip. The patch set uses engine.stamp to select engine-matched mirror assets for dart-sdk, flutter_patched_sdk(_product), and linux-<host-arch> host tools. The patch set also whitelists this base URL in Flutter's artifact downloader, so custom mirror downloads do not emit SDK-bug warnings.

The installer also applies a small Flutter framework patch so the tool treats Termux as a Linux-like host for host-platform selection and Android SDK path discovery.

What It Does

By default, ./install.sh:

• clones the latest Flutter tag that still targets Dart 3.7 (3.32.8) if it is not already present
• downloads the latest Termux host bundle release asset
• extracts the bundle
• applies the Termux host compatibility patch
• auto-reclones the Flutter checkout if a previous local patch state is incompatible with the current patch set
• clears stale bin/cache/artifacts/engine/common, linux-arm64, and linux-x64 cache directories before overlaying
• overlays the bionic host tools into the Flutter SDK cache
• normalizes the overlaid Dart SDK semver so pub accepts the prebuilt bundle
• writes env.sh
• writes a flutter-termux wrapper in bin/
• configures engine-stamp keyed Dart mirror env vars to avoid kernel format skew

Current Scope

Current validated host bundle targets:

• arm64 Android / Termux hosts
• x64 Android / Termux hosts

This is aimed at running the Flutter tool itself inside Termux. Android target runtime artifacts still come from the normal Flutter cache flow (flutter precache --android or first use).

Requirements

The installer itself needs:

• git
• tar
• python3
• unzip

On Termux it can install missing prerequisites automatically with pkg.

For actual Flutter app builds you still need the normal platform dependencies:

• Android APK builds:
  • Java/JDK
  • Android SDK command-line tools or Android Studio
  • accepted Android licenses
• Web builds:
  • Flutter web artifacts (flutter precache --web)
  • a browser for local debug if you want flutter run -d chrome

Install

git clone https://github.com/sirvkrm/flutter-android-bionic-termux-installer.git
cd flutter-android-bionic-termux-installer
chmod +x install.sh
./install.sh

Default install root on Termux:

$PREFIX/opt/flutter-termux

That produces:

• flutter/ for the Flutter SDK checkout
• env.sh
• bin/flutter-termux

Choose A Release

Install a specific tag:

./install.sh --tag v2026.03.04

Choose an asset interactively:

./install.sh --tag v2026.03.04 --interactive

Install a specific host bundle asset:

./install.sh --tag v2026.03.04 --asset flutter-android-bionic-termux-host-x64-20260304.tar.gz

List release tags:

./install.sh --list-releases

Flutter SDK Options

Use a different install root:

./install.sh --install-root "$HOME/my-flutter-termux"

Reuse or target a different Flutter checkout path:

./install.sh --flutter-dir "$HOME/flutter-termux-sdk"

If an existing checkout is present at a different Flutter ref, the installer now replaces it automatically. Use --reclone if you want to force a fresh clone even when the checkout already matches the requested ref.

Clone a different Flutter ref:

./install.sh --flutter-ref master

The default ref is intentionally pinned to 3.32.8, because the current public engine source used to build the bionic host bundle still provides Dart 3.7. Newer Flutter framework refs such as current stable require newer Dart SDK versions and will fail during flutter_tools bootstrap with this host bundle.

Override Dart mirror owner/repo:

./install.sh --dart-owner sirvkrm --dart-repo dart-android-bionic-builder

Run Android precache immediately after install:

./install.sh --precache

After Install

Load the environment:

source "$PREFIX/opt/flutter-termux/env.sh"

Or use the wrapper directly:

$PREFIX/opt/flutter-termux/bin/flutter-termux --version

Recommended first checks:

flutter --version
flutter doctor -v
flutter precache --android

If your Android SDK was not auto-detected, set these in env.sh:

export ANDROID_HOME="$HOME/Android/Sdk"
export ANDROID_SDK_ROOT="$HOME/Android/Sdk"

Engine-stamp specific mirror variables written by installer:

export FLUTTER_TERMUX_ENGINE_STAMP="..."
export FLUTTER_TERMUX_HOST_ARCH="arm64|x64"
export FLUTTER_TERMUX_ARTIFACT_BASE_URL="https://github.com/sirvkrm/flutter-android-bionic-builder/releases/download/<tag>"
export FLUTTER_TERMUX_DART_ARTIFACT_BASE_URL="https://github.com/sirvkrm/dart-android-bionic-builder/releases/download/<tag>"
export FLUTTER_TERMUX_DART_SDK_ASSET="dart-sdk-android-<host-arch>-<engine-stamp>.zip"

If your NDK is installed in Termux build-tools, also set:

export ANDROID_NDK_HOME="$HOME/.build-tools/android/android-ndk-r27c"

Patch Files

The Flutter framework patches applied during install are stored here:

• patches/0001-termux-android-host-support.patch
• patches/0002-termux-android-flutter-cache-support.patch
• patches/0003-termux-android-web-chrome-support.patch
• patches/0004-termux-android-adb-discovery-tolerance.patch
• patches/0005-termux-android-artifact-namespace-and-mirror.patch
• patches/0006-termux-android-allow-custom-artifact-base-url.patch
• patches/0007-termux-android-dart-sdk-mirror.patch
• patches/0008-termux-android-gradle-wrapper-shell.patch

Limitations

• Host bundles are published per host arch (arm64 and x64).
• This installer patches the Flutter framework checkout locally; if you switch branches or reset the SDK repo, re-run the installer.
• The builder repo must publish flutter-android-bionic-termux-host-<host-arch>-*.tar.gz for the selected release tag.