simple-qt-app

A minimal "Hello World" Qt C++ application with multiple build options.

Structure

simple-qt-app/
  app/
    main.cpp              # Qt hello world (QApplication + QLabel)
    CMakeLists.txt        # CMake build config
    macos/
      Info.plist.in       # macOS bundle Info.plist template
  nix/
    app.nix               # Nix derivation to build the app
    macos-bundle.nix      # Creates macOS .app bundle
    macos-dmg.nix         # Creates DMG installer
  flake.nix               # Nix flake with app, app-bundle, dmg outputs
  compile.sh              # Shell script for local compilation

Building

Option 1: Local Build with compile.sh

Requires Qt6, CMake, and Ninja installed on your system:

./compile.sh

This will build the app in the build/ directory. Run with:

./build/HelloWorld

Option 1b: Local DMG Build with dmg.sh (macOS only)

Build a DMG using local tools (uses compile.sh internally):

./dmg.sh

This will:

1. Compile the app using compile.sh
2. Create a .app bundle with all necessary Qt frameworks
3. Fix library paths and codesign
4. Create a distributable DMG at build/HelloWorld-1.0.0.dmg

Note: The script will use macdeployqt (Qt's official bundling tool) if available, which ensures all dependencies are properly bundled. If macdeployqt is not found, it falls back to manual bundling which may not catch all dependencies.

For production/distribution: Consider using nix build '.#dmg' which provides more reliable dependency management and produces a truly self-contained app.

Option 2: Nix Build

Build the app with Nix:

nix build

Run with:

./result/bin/HelloWorld

Option 3: macOS DMG (macOS only)

Build a distributable DMG:

nix build '.#dmg'

The DMG will be created at ./result/HelloWorld.dmg

You can also build just the .app bundle:

nix build '.#app-bundle'

Development

Enter the Nix development shell:

nix develop

This provides all necessary build tools (CMake, Ninja, Qt6) in an isolated environment.

Verifying DMG Self-Containment

./check-bundle-refs.sh ./build/HelloWorld-1.0.0.dmg

./check-nix-refs.sh ./build/HelloWorld-1.0.0.dmg