MultiMC5/BUILD.md

Build Instructions

Contents

• Note
• Getting the source
• Linux
• Windows
• macOS

Note

MultiMC is a portable application and is not supposed to be installed into any system folders. That would be anything outside your home folder. Before running make install, make sure you set the install path to something you have write access to. Never build this under an administrator/root level account. Don't use sudo. It won't work and it's not supposed to work. Also note that this guide is for development purposes only.
No support is given for building your own fork or special build for any reason whatsoever.

Branding, identifying marks and API keys

The logo and related assets are All Rights Reserved and may only be used in official builds of MultiMC hosted on multimc.org, and as such, are not, and will not be included in this repository. The source is only provided for the purpose of collaboration.

API keys are necessary for Microsoft account functionality. More info in (Not) Secrets

Getting the source

Clone the source code using git and grab all the submodules:

git clone https://github.com/MultiMC/Launcher.git
git submodule init
git submodule update

Linux

Getting the project to build and run on Linux is easy if you use any modern and up-to-date linux distribution.

Build dependencies

• A C++ compiler capable of building C++17 code.
• Qt 6.2+ Development tools (http://qt-project.org/downloads) ("Qt Online Installer for Linux (64 bit)") or the equivalent from your package manager. It is always better to use the Qt from your distribution, as long as it has a new enough version.
• cmake 3.22 or newer
• Java JDK 8 (for example, openjdk-8-jdk)
• GL headers (for example, libgl1-mesa-dev)

Building from command line

You need a source folder, a build folder and an install folder.

Let's say you want everything in ~/MultiMC/:

# make all the folders
mkdir ~/MultiMC && cd ~/MultiMC
mkdir build
mkdir install
# clone the complete source
git clone --recursive https://github.com/MultiMC/Launcher.git src
# configure the project
cd build
cmake -DCMAKE_INSTALL_PREFIX=../install ../src
# build & install (use -j with the number of cores your CPU has)
make -j8 install

You can use IDEs like KDevelop or QtCreator to open the CMake project if you want to work on the code.

Installing Qt using the installer (optional)

1. Run the Qt installer.
2. Choose a place to install Qt.
3. Choose the components you want to install.
   • You need Qt 6.5.x 64-bit ticked.
   • You need Tools/Qt Creator ticked.
   • You need The extra Core5Compat library ticked.
   • Other components are selected by default, you can untick them if you don't need them.
4. Accept the license agreements.
5. Double check the install details and then click "Install".
   • Installation can take a very long time, go grab a cup of tea or something and let it work.

Loading the project in Qt Creator (optional)

1. Open Qt Creator.
2. Choose File->Open File or Project.
3. Navigate to the Launcher source folder you cloned and choose CMakeLists.txt.
4. Read the instructions that just popped up about a build location and choose one.
5. You should see "Run CMake" in the window.
   • Make sure that Generator is set to "Unix Generator (Desktop Qt 5.6.x GCC 64bit)".
   • Hit the "Run CMake" button.
   • You'll see warnings and it might not be clear that it succeeded until you scroll to the bottom of the window.
   • Hit "Finish" if CMake ran successfully.
6. Cross your fingers and press the Run button (bottom left of Qt Creator).
   • If the project builds successfully it will run and the Launcher window will pop up.

If this doesn't work for you, let us know on IRC (Esper/#MultiMC)!

Windows

Getting the project to build and run on Windows is easy if you use Qt's IDE, Qt Creator. The project will simply not compile using Microsoft build tools, because that's not something we do. If it does compile, it is by chance only.

Dependencies

• Qt 6.5+ Development tools -- Qt Online Installer for Windows
• Java JDK 8 - Use the MSI installer.
• CMake -- Windows (Win32 Installer)

Ensure that Java and CMake are on PATH.

Getting set up

Installing Qt

1. Run the Qt installer
2. Choose a place to install Qt (C:\Qt is the default),
3. Choose the components you want to install
   • You need Qt 6.5 ticked.
   • You need Tools/Qt Creator ticked.
   • You need The extra Core5Compat library ticked.
   • Other components are selected by default, you can untick them if you don't need them.
4. Accept the license agreements,
5. Double check the install details and then click "Install"
   • Installation can take a very long time, go grab a cup of tea or something and let it work.

Installing CMake

1. Run the CMake installer,
2. It's easiest if you choose to add CMake to the PATH for all users,
   • If you don't choose to do this, remember where you installed CMake.

Loading the project

1. Open Qt Creator,
2. Choose File->Open File or Project,
3. Navigate to the Launcher source folder you cloned and choose CMakeLists.txt,
4. Read the instructions that just popped up about a build location and choose one,
5. If you chose not to add CMake to the system PATH, tell Qt Creator where you installed it,
   • Otherwise you can skip this step.
6. You should see "Run CMake" in the window,
   • Make sure that Generator is set to "MinGW Generator (Desktop Qt 5.6.x MinGW 32bit)",
   • Hit the "Run CMake" button,
   • You'll see warnings and it might not be clear that it succeeded until you scroll to the bottom of the window.
   • Hit "Finish" if CMake ran successfully.
7. Cross your fingers and press the Run button (bottom left of Qt Creator)!
   • If the project builds successfully it will run and the Launcher window will pop up,
   • Test OpenSSL by making an instance and trying to log in. If Qt Creator couldn't find OpenSSL during the CMake stage, login will fail and you'll get an error.

macOS

Install prerequisites:

• Install XCode Command Line tools
• Install the official build of CMake (https://cmake.org/download/)
• Install JDK 8 (https://www.oracle.com/java/technologies/javase/javase-jdk8-downloads.html)
• Get Qt 6.5 and install it

XCode Command Line tools

If you don't have XCode CommandLine tools installed, you can install them by using this command in the Terminal App

xcode-select --install

Build

Pick an installation path - this is where the final .app will be constructed when you run make install. Supply it as the CMAKE_INSTALL_PREFIX argument during CMake configuration.

git clone --recursive https://github.com/MultiMC/Launcher.git
cd Launcher
mkdir build
cd build
cmake \
 -DCMAKE_C_COMPILER=/usr/bin/clang \
 -DCMAKE_CXX_COMPILER=/usr/bin/clang++ \
 -DCMAKE_BUILD_TYPE=Release \
 -DCMAKE_INSTALL_PREFIX:PATH="$(dirname $PWD)/dist/" \
 -DCMAKE_PREFIX_PATH="/path/to/Qt6.5/" \
 ..
make install

Note: The final app bundle may not run due to code signing issues, which need to be fixed with codesign -fs -.