Compiling Mudlet

From Mudlet
Jump to navigation Jump to search

If you just want to use Mudlet, you can skip these steps, and use one of the already ready (pre-compiled) installers ready for download.

Otherwise, hop in for new adventure!

Easy Mudlet code understanding.png

Key contributing information

Clang format is used to automatically format code submissions using the src/.clang-format style. See here how to enable clang-format with Qt Creator - and make sure to specify the 'File' option for the configuration style.

Branches:

development is the development branch where new features can go.

Workflow:

Fork and submit a PR with your changes (Github tutorial).

Here is a list of package versions delivered with different Linux distros. You may want to upgrade these: https://repology.org/project/mudlet/versions

Compiling

Compiling on Ubuntu

These instructions will get you setup compiling on Ubuntu. Need a hand? Join us on Mudlet's Discord or forums.

Ubuntu 20.10

Following instructions will work on Ubuntu 20.10 as well as all it's flavours and derivatives (such as KDE Neon, for example) Important thing is to have Universe repository enabled in your package manager.

Necessary dependencies

Majority of required dependencies can be obtained from repositories, and can be installed with following command:

 sudo apt-get install build-essential git liblua5.1-dev zlib1g-dev libhunspell-dev libpcre3-dev libzip-dev libboost-dev libyajl-dev libpulse-dev lua-rex-pcre lua-filesystem lua-zip lua-sql-sqlite3 qt5-default qtmultimedia5-dev qttools5-dev luarocks ccache libpugixml-dev lua5.1 libpcre3-dev  libhunspell-dev libzip-dev  libglu1-mesa-dev ccache mesa-common-dev libpulse-dev libglib2.0-dev luarocks libboost-all-dev libgstreamer1.0-dev qt5keychain-dev libsecret-1-dev

Few of required Lua modules are not available in official repositories, so they have to be installed using luarocks

 sudo luarocks install lcf
 sudo luarocks install luautf8
 sudo luarocks install lua-yajl

Obtaining the source code

If you're compiling Mudlet from source for everyday use with few more features that are not present in official AppImage, it is strongly advised that you obtain and compile the source code latest stable release of Mudlet. At the moment of writing this article, current stable version is 4.10.1, you'll need to adjust version number if new release comes out at later date.

 mkdir build && cd build
 wget https://www.mudlet.org/wp-content/files/Mudlet-4.10.1.tar.xz
 tar xvf Mudlet-4.10.1.tar.xz
 cd src
 

However, if you're feeling adventurous and wish to play with the latest development code, you can obtain it directly from Mudlet's Git repository:

 git clone -b development https://github.com/Mudlet/Mudlet.git
 cd Mudlet/src/

Compiling the code

Following commands will configure the code to install Mudlet on a system level and compile it. If you wish to install it somewhere else, you may adjust both paths in following command to point to desired destination before compiling it with make. (Rest of this guide will assume you're installing on a system level)

 WITH_FONTS=NO WITH_OWN_QTKEYCHAIN=NO WITH_UPDATER=NO WITH_VARIABLE_SPLASH_SCREEN=NO XDG_DATA_DIRS=/usr/share qmake PREFIX=/usr
 make
 
Compiling on Ubuntu for Raspberry Pi

Ubuntu for Raspberry Pi is essentially the same as Ubuntu for regular PC, however, due to sketchy state of OpenGL drivers on RPi 4, you'll likely need to disable Mudlet's 3D Mapper or code will just not compile. Adjusted commands are:

 WITH_3DMAPPER=NO WITH_FONTS=NO WITH_OWN_QTKEYCHAIN=NO WITH_UPDATER=NO WITH_VARIABLE_SPLASH_SCREEN=NO XDG_DATA_DIRS=/usr/share qmake PREFIX=/usr
 make

Installing compiled code

After successful code compilation, next few commands will install resulting binaries, desktop file for menus and appropriate icon.

 sudo make install
 sudo cp ../mudlet.png /usr/share/pixmaps
 sudo cp ../mudlet.desktop /usr/share/applications
 

Optional additional software

One of the major reasons for compiling Mudlet from source is the ability to unlock more features that are not enabled in official AppImage. Manual compilation will resolve the issues with sound by using system provided libraries, as well as enable more detailed theming of Mudlet application itself. However, do take note that Mudlet is a Qt based program, and that theming will not 'just work' in GTK based desktop environments (Gnome, XFCE, MATE, Budgie).

 sudo apt install qt5ct

will install a tool for configuration of look and feel of Qt programs inside those desktop environments. Users of Qt based Desktop environments (KDE Plasma, LXQT) can simply use settings provided by environment itself.

Many of Qt widget styles and color schemes are available in official repositories, and will make Mudlet better.

Mudlet on Wayland

Mudlet compiled like this will run and work on Wayland, however, there are a few quirks with Keybidings (Numpad may not work as expected). Until that is resolved you may wish to start mudlet with:

 QT_QPA_PLATFORM=xcb mudlet

(enter in terminal or simply change the Exec= line in /usr/share/applications/mudlet.desktop)

Uninstallation

You can reverse the process described in this guide with following command:

 sudo rm -fr /usr/bin/mudlet /usr/share/mudlet /usr/share/applications/mudlet.desktop /usr/share/pixmaps/mudlet.png

Ubuntu 18.04 setup

For Ubuntu 18.04 see the instructions for Compiling on Debian 9 'Stretch' (tested working perfectly).


1. Ubuntu 18.04 setup

If you're on Ubuntu 18.04 (Bionic Beaver), install the following. If you're on a newer Ubuntu, skip this step and go to 2. Install dependencies.

 sudo add-apt-repository ppa:beineri/opt-qt-5.12.3-bionic
 sudo apt update
 sudo apt install qt512-meta-full qt512creator
 source /opt/qt512/bin/qt512-env.sh

2. Install dependencies

sudo apt install git build-essential qt5-default qtmultimedia5-dev qttools5-dev \
  lua5.1 liblua5.1-0-dev libpcre3-dev libboost-dev zlib1g-dev cmake \
  libhunspell-dev lua-rex-pcre lua-sql-sqlite3 lua-filesystem lua-zip libyajl-dev \
  libzip-dev libgstreamer0.10-0 libglu1-mesa-dev ccache libpugixml-dev \
  mesa-common-dev qtcreator libpulse-dev libglib2.0-dev luarocks libboost-all-dev \
  libsecret-1-dev
sudo apt install gstreamer0.10-fluendo-mp3 # may not work on newer Ubuntu
sudo luarocks install luautf8
sudo luarocks install lua-yajl

3. Get Mudlet source

git clone --recursive https://github.com/Mudlet/Mudlet.git mudlet

4. Create a build directory

 cd mudlet
 mkdir build
 cd build

5. Run the following commands, depending on which build system you want to use

EITHER:

cmake ..

OR:

qmake CONFIG+=debug ../src/mudlet.pro

THEN:

make -j `nproc`

5. Start the application you have just compiled - enjoy

cd src
./mudlet

Compiling on Chrome OS

These instructions will get you setup compiling on Chrome OS. Need a hand? Join us on Mudlet's Discord or forums.

1. Install dependencies

sudo apt install git build-essential qt5-default qtmultimedia5-dev qttools5-dev \
  lua5.1 liblua5.1-0-dev libpcre3-dev libboost-dev zlib1g-dev cmake \
  libhunspell-dev lua-rex-pcre lua-sql-sqlite3 lua-filesystem lua-zip libyajl-dev \
  libzip-dev libglu1-mesa-dev ccache libpugixml-dev mesa-common-dev qtcreator \
  libpulse-dev libglib2.0-dev luarocks libboost-all-dev
sudo luarocks install luautf8
sudo luarocks install lua-yajl

You'll also need to download a few files from the web and install them locally.

libgstreamer0.10 - gstreamer0.10-fluendo-mp3 - liboil0.3

3. Get Mudlet source

git clone --recursive https://github.com/Mudlet/Mudlet.git mudlet

4. Create a build directory

 cd mudlet
 mkdir build
 cd build

5. Run the following command

qmake CONFIG+=debug ../src/mudlet.pro

then:

make

5. Start the application you have just compiled - enjoy

./mudlet

Compiling on macOS

These instructions will get you setup compiling on macOS. Need a hand? Join us on Mudlet's Discord server or forums otherwise.


1. Install prerequisites

Install XCode, command line tools for XCode, and HomeBrew.

Once everything is installed, do:

 brew doctor
 brew update
 brew install git

2. Get Mudlet source

 git clone --recursive https://github.com/Mudlet/Mudlet.git mudlet

3. Go to the parent of the mudlet "src" folder and create (if necessary) a build subdirectory (this is so that we can build out of source which keeps the source code clean)

 mkdir build

3. Setup your environment you only need the first three lines if your system cannot find the right Qt libraries or tools, the added directories might be different if you have installed them differently

 export PATH="/usr/local/opt/qt5/bin:$PATH"
 export LDFLAGS=" -L/usr/local/opt/qt5/lib ${LDFLAGS}"
 export CPPFLAGS=" -I/usr/local/opt/qt5/include ${CPPFLAGS}"
 ../mudlet/CI/travis.osx.before_install.sh
 ../mudlet/CI/travis.osx.install.sh
 luarocks config lua_version 5.1
 eval `luarocks path --lua-version=5.1`
 luarocks --lua-version=5.1 --lua-dir=`brew --prefix [email protected]` install lrexlib-pcre
 brew install sqlite
 luarocks --lua-version=5.1 --lua-dir=`brew --prefix [email protected]` install luasql-sqlite3 SQLITE_DIR=`brew --prefix sqlite` 
 luarocks --lua-version=5.1 --lua-dir=`brew --prefix [email protected]` install luautf8
 luarocks --lua-version=5.1 --lua-dir=`brew --prefix [email protected]` install lua-yajl
 luarocks --lua-version=5.1 --lua-dir=`brew --prefix [email protected]` install luafilesystem
 luarocks --lua-version=5.1 --lua-dir=`brew --prefix [email protected]` install lua-zip
 brew install p7zip
 export BOOST_ROOT="$(pwd)/../mudlet/3rdparty/boost"
 export BOOST_URL="https://sourceforge.net/projects/boost/files/boost/1.72.0/boost_1_72_0.tar.bz2/download"
 mkdir -p $BOOST_ROOT
 curl --progress-bar --location --output $BOOST_ROOT/download.tar.bz2 $BOOST_URL
 7z -o$BOOST_ROOT x $BOOST_ROOT/download.tar.bz2 -y -bd
 7z -o$BOOST_ROOT x $BOOST_ROOT/download.tar -y -bd
 cd $BOOST_ROOT && cp -r boost_*/* .
 rm -rf boost_*/* download.tar.bz2 download.tar

4. Run the following commands

 cd ../../../build
 cmake ../mudlet -DCMAKE_PREFIX_PATH=`brew --prefix qt5`
 make -j `sysctl -n hw.ncpu`


5. Enjoy

The Mudlet.app is now available in build/ or src/ for launching.

Compiling on Debian 'Sid'

1. Install required packages from main repo.

sudo apt-get install build-essential git liblua5.1-dev zlib1g-dev libhunspell-dev libpcre3-dev \
libzip-dev libboost-dev libyajl-dev libpulse-dev lua-rex-pcre lua-filesystem lua-zip \
lua-sql-sqlite3 qt5-default qtmultimedia5-dev qttools5-dev luarocks ccache libpugixml-dev
sudo luarocks install luautf8
sudo luarocks install lua-yajl

2. Grab latest Mudlet source.

mkdir ~/projects && cd ~/projects && git clone --recursive https://github.com/Mudlet/Mudlet.git mudlet

3. Build Mudlet.

cd ~/projects/mudlet/src
qmake
make
sudo make install

Compiling on Debian 10 'Buster'

1. Install required packages.

sudo apt-get install build-essential git liblua5.1-dev zlib1g-dev libhunspell-dev libpcre3-dev \
libzip-dev libboost-dev libyajl-dev libpulse-dev lua-rex-pcre lua-filesystem lua-zip \
lua-sql-sqlite3 qt5-default qtmultimedia5-dev qttools5-dev luarocks ccache libpugixml-dev \
libqt5texttospeech5-dev qtspeech5-flite-plugin qtspeech5-speechd-plugin libqt5opengl5-dev
sudo luarocks install luautf8  
sudo luarocks install lua-yajl

2. Get Mudlet source.

mkdir ~/source && cd ~/source
git clone --recursive https://github.com/Mudlet/Mudlet.git

Note: the line above will check out `development` branch source code, and this might not always be stable. You can check out the latest release source code using this command:

git clone --recursive --branch main https://github.com/Mudlet/Mudlet.git

3. Build Mudlet.

mkdir ~/source/Mudlet/build && cd ~/source/Mudlet/build
qmake ../src/mudlet.pro
make -j `nproc`
sudo make install

After these steps you can run Mudlet by typing:

mudlet

Compiling on Raspberry Pi OS

These instructions will get you compiling and running Mudlet on Raspberry Pi OS (Buster). Need a hand? Join us on Mudlet's Discord or forums.

1.a Install apt dependencies

sudo apt-get update
sudo apt-get install build-essential git liblua5.1-dev zlib1g-dev libhunspell-dev libpcre3-dev \
  libzip-dev libboost-graph-dev libyajl-dev libpulse-dev lua-rex-pcre lua-filesystem lua-zip \
  lua-sql-sqlite3 qt5-default qtmultimedia5-dev qttools5-dev luarocks ccache libpugixml-dev cmake


installing apt dependencies

1.b Install luarocks dependencies

sudo luarocks install luautf8  
sudo luarocks install lua-yajl YAJL_LIBDIR=/usr/lib/arm-linux-gnueabihf/ YAJL_INCDIR=/usr/include


after luarocks dependencies

2. Get Mudlet source

mkdir ~/source && cd ~/source 
git clone https://github.com/Mudlet/Mudlet.git
After cloning

3. Create a build directory

 cd Mudlet && mkdir build && cd build

4. Run the following commands to build

WITH_UPDATER=NO WITH_3DMAPPER=NO qmake ../src/mudlet.pro
If you get a response along the lines of:
qmake: could not find a Qt installation of 
then you likely have qtchooser present in your system that allows for both Qt4 and Qt5 (or more than one Qt5 version) and it modifiers qmake and some other Qt development programs to take an additional argument to specify which version to use. In that case you should use:
WITH_UPDATER=NO WITH_3DMAPPER=NO qmake -qt=qt5 ../src/mudlet.pro
After qmake

THEN:

For the fastest compile time, 15-20min on a RPi4 with 4GB of ram
make -j `nproc`

OR:

If you want to use your Pi while it builds or have an older Raspberry Pi, be prepared for it to take a while (over an hour) - it is not recommended to try to more than one compilation task at a time on the older systems with the -j option as they will only have a system memory with enough space for one of some of those tasks:
make
Success!

4. Install the application you have just compiled

sudo make install
Installed now

5. Enjoy!

# mudlet is in the path, can just run it
mudlet

Compiling on ArchLinux

Mudlet is available in the Arch User Repository.

To install it use your favourite AUR helper (helper tool will automatically resove dependancies); example using yay :

yay -S mudlet

For more info on this process, visit Arch User Repository - ArchWiki.

Note: For the most recent development version of Mudlet, replace 'mudlet' with 'mudlet-git' in the above commands and proceed as described.

Built in fonts have been disabled, but are available in packages listed as optional dependancies.

Discord support in Mudlet depends on an extrenal library provided by discord-rpc-api, which is also available in AUR, choose whichever variant suits you best.

Compiling on Gentoo

An overlay containing Mudlet is available for compiling Mudlet on Gentoo.

Compiling on Windows

These instructions will get you setup compiling on Windows.

Need a hand? Join us on the Mudlet Discord server or forums.

1. Download Mudlet source code

  1. Install Github Desktop.
  2. Clone (instructions) Mudlet's repository to your local drive.

Note Note: You must use a location on C:\ without any spaces in folder names!

2. Perform a one-time setup

Right-click on setup-windows-sdk.ps1 and select Run with PowerShell. This will automatically download all of the requires tools (including Python 2) and libraries, set them up for you, build Mudlet, and launch it! If this script exits immediately, please upgrade your PowerShell version first.

Note Note: Depending on your Internet connection and computer speed, this one-time setup will take 30 minutes or more - so grab a cup of tea or coffee.

Sometimes the output will get stuck and not progress - just press Enter to make it continue. This is a well-known Powershell bug.

During the installation, you'll see the Qt installer window pop-up - this is normal:

Qt-installer.gif

The Qt installer might ask you about your data collection preferences - answer as you wish and the automated install will continue:

Qt-installer-data-collection.png

The installer's final step will be compiling all of the source code, which looks like this:

Compiling-step.gif

After it's all done, a Mudlet version ending in "-dev" will launch automatically:

Mudlet-launching.gif

If something didn't work right, you can check out the verbose log that is available at C:\src\verbose_output.log.

Coding on Mudlet

Open C:\<path to repository>\src\mudlet.pro in Qt Creator, which resides here: C:\Qt\Tools\QtCreator\bin\qtcreator.exe. Then enable Debug and Release builds and hit Configure Project:

Selection 173.png

Press Ctrl+5 and update project settings. Check how many logical processors are available in your system with the Task Manager:

2 processors are available in this example

And set this amount in Qt Creator:

Change Qt Creator to use many cores.gif

Hit run:

Selection 176.png

Click on Compile Output to see progress on compiling:

Selection 177.png

When it's all ready, the new Mudlet with your changes will launch. You're all done!

Contributing changes

Once you're all done with your changes, contribute them to Mudlet using a pull request. Thanks for improving open-source!

Uninstalling

To get rid of everything, uninstall Qt using the C:\Qt\MaintenanceTool.exe and remove the following folders:

C:\Libraries
C:\LuaRocks
C:\MinGW
C:\Python27
C:\Qt
C:\src

Compiling on Github Codespaces

Github Codespaces allow you to code and run Mudlet all from the browser - makes it a lot easier to get started. It also allows you to code Mudlet itself from any computer in the world! As for this time Github Codespaces is in a private beta, so make sure to apply here.

1. Create a new codespace

Create a new Codespace by going to github.com/codespaces using Google Chrome or Microsoft Edge (Firefox at the time of the writing doesn't have working copy/paste).

New codespace.png

2. Wait for it to load

This will take a while (~5min) so grab a tea:

Building Visual Studio Codespace.png

3. Connect to the environment

Go to the Remote Explorer on the side:

Remote explorer.png

Then connect to your online Linux desktop with mudlet as the password on port 6080. We chose a retro 90's look here to fit with the whole hacking theme 😉

Connect to remote machine.png

4. Build Mudlet

In Codespaces, hit F7 and select Let CMake guess...

CMake configuration.png

It will then start building Mudlet automatically. Using the Basic instance (only kind available in beta) the first-time build will take ~25min, so take a break here - you've made excellent progress. All follow-up compiles after this will be quicker, by the way.

Building Mudlet in codespaces.png

5. Run Mudlet

Launch Mudlet.png

Hit the little play button at the bottom of the screen, and Mudlet will now launch in the remote connection tab. Not working? We can help. Otherwise, enjoy!

Mudlet running remotely.png

Note: When the codespace is unused for a while, it will disconnect. It'll never disconnect while you're actively using it. See Github issue for details.

Compiling on Windows 7+ (MSYS2 Alternative)

INCOMPLETE, IN PROGRESS

Go to http://www.msys2.org/ to download the 64 bit MSYS2 installer (as of 2020/05/24 32 bit hosts - for compiling software, but not for using code built with it) have been deprecated, the last installer for that 32-bit systems is held at: http://repo.msys2.org/distrib/i686/msys2-i686-20190524.exe ) and follow the installation instructions (Steps 1 to 8 on that page), these instructions assume that "C:\msys64" or "C:\msys32" is used depending on the bitness of the system it is being installed on.

Install the following packages (using "pacman -S packageName"), the ones with a -i686- in the middle are the ones for 32-bit (i686) targets and -x86_64- are the ones for 64-bit targets - it is possible to install both for building Mudlet for target PCs of both bitnesses on a 64-bit host, it is not clear whether the reverse is true with a 32-bit host. These will pull in a number of other required packages as well:

For 32-Bit Mudlet builds:
MINGW64 user@computer ~
$ pacman -S base-devel git mercurial cvs wget ruby zip p7zip python mingw-w64-i686-toolchain mingw-w64-i686-qt-creator mingw-w64-i686-libzip mingw-w64-i686-pugixml mingw-w64-i686-lua51 mingw-w64-i686-lua51-lpeg mingw-w64-i686-lua51-lsqlite3 mingw-w64-i686-lua51-luarocks mingw-w64-i686-hunspell mingw-w64-i686-boost mingw-w64-i686-yajl mingw-w64-i686-clang mingw-w64-i686-cmake mingw-w64-i686-SDL unzip
For 64-Bit Mudlet builds:
MINGW64 user@computer ~
$ pacman -S base-devel git mercurial cvs wget ruby zip p7zip python mingw-w64-x86_64-toolchain mingw-w64-x86_64-qt-creator mingw-w64-x86_64-libzip mingw-w64-x86_64-pugixml mingw-w64-x86_64-lua51 mingw-w64-x86_64-lua51-lpeg mingw-w64-x86_64-lua51-lsqlite3 mingw-w64-x86_64-lua51-luarocks mingw-w64-x86_64-hunspell mingw-w64-x86_64-boost mingw-w64-x86_64-yajl mingw-w64-x86_64-clang mingw-w64-x86_64-cmake mingw-w64-x86_64-SDL unzip
The *-zziplib libraries are used by the luazip luarock {from the Kepler project} but Mudlet will work perfectly well with the alternative lua-zip {from the brimworks GitHub repository - which also provides the lua-yajl rock} which does not require this library - although it is possible that it might still be pulled into the system as a dependency of another MSYS2 package.
Note that this will install the MSYS2 builds of the Qt Libraries and Creator IDE - THE ON/OFF-LINE INSTALLER OF THE QT LIBRARIES AND CREATOR VIA DOWNLOADS FROM QT ARE NOT USEFUL IN THIS SETUP!
Warning
If one is planning to build both bitness binaries an additional step is necessary as, by default, the MSYS2/Mingw-w64 luarocks setup seems to place any .lua or .dll modules it builds/installs on a per user (the so-called local basis) into the same directories with the same names. This is no good for two reasons:
  • It is difficult to work out which bitness a particular module is for and whilst 32-bit modules might work in a 64-bit environment the reverse is definitely not the case
  • It confuses the Luarocks package management systems (as effectively there will be two different luarocks systems operated side-by-side)

This can be worked around by:

  • Editing the .\etc\luarocks\config-5.1.lua for each bitness (Note: this file also needs editing of a different entry in the 32-bit case to work around a different problem below) so that the rocks_trees table entry for the user key is changed from this in both files:
    { name = [[user]], root = home..[[/.luarocks]] },

to something different for each of them, say, for example, for the the 64-bit one:

    { name = [[user]], root = home..[[/.luarocks-x64]] },
  • specifying the rocktree name (user) on the command line when installing or building a luarock with the --tree user argument - note that for some inexplicable reason the --local argument that should do the same thing does not seem to work for these two actions, it is not clear whether this is a MSYS2/Mingw-w64 specific issue or it goes further upstream to Luarocks in general. Thus, in the next step it will be necessary to change from using:
MINGW64 user@computer ~
$ luarocks install --local rockname

to, for the example given:

MINGW64 user@computer ~
$ luarocks install --tree user rockname

where user is the literal string "user" to match the Lua table key in the rock_trees and not, in this case, a representation of the user-name/account of the person performing the action.

From the Windows Start menu start a shell appropriate for the target with the bitness to be built for i.e. "MSYS2 Mingw 32-Bit" or "MSYS2 Mingw 64-Bit". This will likely position the current directory to the root directory of the MSYS2 environment, the text about the prompt line (the one with the "$") will contain three different bits of colored text username@computername; one of MSYS2/MINGW32/MINGW depending on the type of shell you currently in use and / representing the root directory (which will actually be the directory MSYS2 was installed to, for example on the author's system this is "C:/msys64"). Change to the home directory in MYSY by entering "cd" on its own with no argument (it will show up as ~ and it would work out to be, for user to be c:/msys64/home/user or c:/msys32/home/user (if both bitnessess are to be built it will be necessary to repeat the following step twice, one for each and also observe the steps in the above warning) install the following luarocks:

rockname
lrexlib-pcre
lua-yajl
luafilesystem
luasql-sqlite3
luautf8
luazip or lua-zip

by using:

MINGW64 user@computer ~
$ luarocks install [--local] rockname

The --local argument is an optional one that causes the luarock and the lua module to be installed on a per-user basis rather than on a system wide one, this may be important if the PC is used by multiple users and more than one of them uses Lua in any form.

There was a bug (reported upstream as msys2/MINGW-packages Issue #5928) but now believed to be resolved where the 32-Bit Luarocks version messed up a couple of configuration files on installation and luarocks was unable to work without editing them:
Edit /mingw32/share/lua/5.1/luarocks/site_config.lua by changing the six lines with paths (in [[...]]) that start with /mingw32 to prepend the drive and path of the MSYS2 install {e.g. C:/msys64 or C:/msys32 if following the previous directions), e.g. the line:
 site_config.LUAROCKS_PREFIX=[[/mingw32]]
on 64-bit systems in the 32-bit part it should be changed to:
 site_config.LUAROCKS_PREFIX=[[C:/msys64/mingw32]]
Also change the line:
 site_config.LUAROCKS_ROCKS_SUBDIR=[[/lib/luarocks/rocks]]
to:
 site_config.LUAROCKS_ROCKS_SUBDIR=[[/lib/luarocks/rocks-5.1]]
Edit /mingw32/etc/luarocks/config-5.1.lua in one place where the path is wrong in the same manner as above, so change:
 { name = [[system]], root = [[/mingw32]] }
to (on 64-bit systems):
 { name = [[system]], root = [[C:/msys64/mingw32]] }]

Now create somewhere to work on the Mudlet source, assuming that other software coding with other pieces of software will be done, create a sub-directory in the home directory, and then make one just for Mudlet under that:

MINGW64 user@computer ~
$ mkdir ./src

MINGW64 user@computer ~
$ mkdir ./src/mudlet

Change to that directory and get the source code:

MINGW64 user@computer ~
$ cd ./src/mudlet

MINGW64 user@computer ~/src/mudlet
$ git clone git://github.com/Mudlet/Mudlet.git .

If you are planning to contribute to the Mudlet code you will want to visit Github and create your own GitHub repository, you can then push commits (changes to the code) to there and raise a Pull Request for a Mudlet Maker to drag the changes over to the above repository. You will want to add your repository and perhaps those of some other contributors so you can track what they are doing and see/try/experiment with their PRs before they get merged. Therefore you will want to add some other repositories into the mix. The names you use to identify those other repositories will show up in any utility that works with the repository you have just created in the above "clone" operation and can be anything you like but it makes sense to have clear names. So to add "myName", and those of the leading active contributors to the Mudlet codebase you will use:

MINGW64 user@computer ~/src/mudlet
$ git remote add Mine https://github.com/myName/Mudlet.git

MINGW64 user@computer ~/src/mudlet
$ git remote add Vadim https://github.com/vadi2/Mudlet.git 

MINGW64 user@computer ~/src/mudlet
$ git remote add SlySven https://github.com/SlySven/Mudlet.git

MINGW64 user@computer ~/src/mudlet
$ git remote add Kebap https://github.com/Kebap/Mudlet.git

Now obtain all the versions of the code with:

MINGW64 user@computer ~/src/mudlet
$ git fetch --all

This will produce a lot of lines of output the first time and it might take a little while on a slow connection...

{Section missing - it turns out that the default GUI git tools that the author of this section would normally use: "gitk" and "git gui" have some problems in the versions currently supplied from the MSYS2 system - and it was necessary to import them from the set that the Git4Win have patched - see https://github.com/git-for-windows/git/wiki/Install-inside-MSYS2-proper }

Some modifications to the qmake/cmake project files are needed and these are now supported in the main development branch in the upstream {the Mudlet organisation's own GitHub repository} which requires that there is an environmental variable WITH_MAIN_BUILD_SYSTEM and it is set to the (case-insensitive) value NO:

MINGW64 user@computer ~/src/mudlet
$ export WITH_MAIN_BUILD_SYSTEM=NO

Also the MINGW_BASE_DIR environmental variable will need to be set to the root directory for the MINGW-W64 installation for the appropriate bitness of the target to be made. For building on a 64-Bit Host {the PC that is compiling the code} to make a 64-Bit application this will likely be C:/msys64/mingw64 and for a 32-Bit application it will probably be C:/msys64/ming32.

E.g.
MINGW64 user@computer ~/src/mudlet
$ export MINGW_BASE_DIR=C:/msys64/mingw64 # To build a 64-Bit Application with a 64-Bit system
Or:
MINGW32 user@computer ~/src/mudlet
$ export MINGW_BASE_DIR=C:/msys64/mingw32 # To build a 32-Bit Application with a 64-Bit system

Now checkout a branch {ideally, if working on solving a new issue, or adding a feature or resolving a bug, one should create a new branch that is a copy of the current, upstream development branch} and then work on it with Qt Creator:

MINGW64 user@computer ~/src/mudlet
$ qtcreator &

Load in the mudlet.pro qmake project file in the src subdirectory (e.g. for this example: c:/msys64/home/user/src/mudlet/src/mudlet.pro) and get hacking...

Setting up IDEs

CLion

If you'd like to use CLion and it is giving the following error:

    By not providing "FindQt5Core.cmake" in CMAKE_MODULE_PATH this project has
    asked CMake to find a package configuration file provided by "Qt5Core", but
    CMake did not find one.

    ...
  

You can fix this by setting -DCMAKE_PREFIX_PATH=<your Qt + version + compiler location>. For example: -DCMAKE_PREFIX_PATH=/media/vadi/SSDer/Programs/Qt/5.15.2/gcc_64/

CLion CMake settings - finidng Qt.png

Visual Studio Code

To set the path in Visual Studio Code, open settings, search for cmake environment and set the CMAKE_PREFIX_PATH to your path, such as /media/vadi/SSDer/Programs/Qt/5.14.1/gcc_64/:

CMake path in Visual Studio Code.png

Building with multiple versions of Lua

Mudlet uses Lua 5.1 only, so if you are compiling on a system that also has later versions installed, you might get the following error: ‘LUA_GLOBALSINDEX’ was not declared in this scope.

To fix this, pass the path to Lua headers explicitly. For CMake: -DLUA_INCLUDE_DIR=/usr/include/lua5.1 (adjust as needed).