EdgeTX Lua compiler action

Precompiles Lua scripts to EdgeTX bytecode (.luac) in GitHub Actions, and publishes a standalone edgetx-luac compiler for Linux, macOS and Windows.

When a radio loads a .lua file, it compiles it on the radio first. Compiling needs much more memory than running the result. On radios with little RAM (X9D, X9 Lite, …) large scripts can fail with "not enough memory" even though they would run fine (EdgeTX#7251). Shipping precompiled .luac files avoids that step.

Compatibility

Action	Bytecode for
v1	EdgeTX 2.11.0 and later

Radios older than 2.11 use a different Lua version and can't load this bytecode.

Usage

- uses: actions/checkout@v7

- uses: EdgeTX/edgetx-luac-action@v1
  with:
    files: |
      SCRIPTS/**/*.lua
      WIDGETS/**/*.lua

This writes a .luac next to each matched .lua file. Then package both files as usual:

- run: zip -r my-scripts.zip SCRIPTS WIDGETS

Inputs

Input	Default	Description
files	**/*.lua	Newline-separated glob patterns, relative to the workspace. ** matches any depth. Files that don't end in .lua are skipped.
strip	true	Strip debug information. The files are smaller, but runtime errors lose line numbers. The radio strips too when it compiles.
check-only	false	Only check syntax and write nothing. This is useful as a lint step on pull requests.
output-dir		Write .luac files here, keeping each script's relative path, instead of next to the source.
edgetx-ref	pinned commit	Branch, tag or full commit SHA of EdgeTX to build the compiler from. Each release of this action pins a tested commit.
edgetx-repo	EdgeTX/edgetx	Repository to build the compiler from, e.g. a fork, to test compiler changes.

Outputs

Output	Description
files	Newline-separated list of the .luac files written.
luac	Path to the edgetx-luac binary, for running it directly in later steps.

Syntax errors appear as annotations on the offending line, and the action then fails.

Symlinked scripts on Windows runners

On Windows, Git checks symlinks out as plain text files holding the link target, so a symlinked .lua file fails to compile. If your repository symlinks scripts and you build on Windows, enable symlinks before checking out:

- run: git config --global core.symlinks true
- uses: actions/checkout@v7

Linux and macOS runners need nothing extra.

Lint on pull requests

- uses: EdgeTX/edgetx-luac-action@v1
  with:
    check-only: true

How the radio chooses between .lua and .luac

When both files exist, the radio loads whichever is newer. The .luac wins if they're the same age. The action writes each .luac after reading its .lua, so the .luac is newer. Zip archives keep those timestamps.

If a user later copies the files in a way that makes the .lua newer, the radio compiles the .lua again, which is exactly what the .luac was meant to avoid. If the .luac can't be loaded (e.g. on an older firmware), the radio falls back to the .lua. So shipping both is the safe default.

Standalone compiler

Every release has edgetx-luac binaries attached:

File	Platform
edgetx-luac-<version>-linux-x64.tar.gz	Linux x86-64 (static)
edgetx-luac-<version>-linux-arm64.tar.gz	Linux ARM64, e.g. Raspberry Pi (static)
edgetx-luac-<version>-macos-universal.tar.gz	macOS, Apple silicon and Intel
edgetx-luac-<version>-windows-x64.zip	Windows x64

SHA256SUMS lists their checksums.

edgetx-luac -s -o script.luac script.lua

The macOS binary isn't signed. Allow it with xattr -d com.apple.quarantine edgetx-luac, or right-click it and choose Open once.

You can also compile in the browser at https://edgetx-luac.pages.dev.

Licence

This action is licensed under the GNU General Public License v2, the same as EdgeTX. The compiler is built from EdgeTX's copy of Lua, which is MIT licensed. The release archives include both licences.

Contributing

See CONTRIBUTING.md for development setup, updating the compiler and releasing.