this script will probably not build proton

build-proton.sh

# Build Proton. Hopefully.
# Note: DO NOT ACTUALLY RUN THIS SCRIPT. Copy/paste each command so if something goes wrong this thing
# doesn't murder your system by accident.
# You should probably run this in a container.
# If you decide to stop it when it is building wine32, make sure you reinstall the 64-bit versions of
# the libraries so you don't have a massive headache while trying to build 64-bit things later on.

git clone --depth 10 https://github.com/ValveSoftware/Proton ./proton --recursive --shallow-submodule
cd proton
# reset all the submodules, no clue why this is needed
git submodule foreach git reset --hard
# common dependencies
sudo apt install git ca-certificates curl gnupg2 software-properties-common gpgv2 gnupg2 gcc g++ g++-multilib mingw-w64 meson
# from Vagrantfile, needed for dxvk
sudo update-alternatives --set x86_64-w64-mingw32-gcc $(which x86_64-w64-mingw32-gcc-posix)
sudo update-alternatives --set x86_64-w64-mingw32-g++ $(which x86_64-w64-mingw32-g++-posix)
sudo update-alternatives --set i686-w64-mingw32-gcc $(which i686-w64-mingw32-gcc-posix)
sudo update-alternatives --set i686-w64-mingw32-g++ $(which i686-w64-mingw32-g++-posix)
# wine build dependencies
# NOTE: if apt complains that it can't find :i386 packages, do sudo dpkg --add-architecture i386
# if updating a previous build, start here and run the following commented out commands:
# $ rm -rf proton-build
# $ git pull
# $ git checkout <new tag>
# $ git submodule update --remote
# NOTE: proton 4.2 does not set the correct branch for the wine submodule, if that is the case, add
# "branch = proton_4.2" to the wine entry in .gitmodules, then run git submodule update --remote again
sudo apt install autoconf autotools-dev bison flex fontforge gawk gettext libacl1-dev libasound2-dev libavcodec-dev libcapi20-dev libdbus-1-dev libfontconfig1-dev libfreetype6-dev libgl1-mesa-dev libglu1-mesa-dev libgphoto2-dev libgsm1-dev libice-dev libjpeg-dev libkrb5-dev liblcms2-dev libldap2-dev libmpg123-dev libopenal-dev libosmesa6-dev libpng-dev libpulse-dev libsane-dev libssl-dev libudev-dev libv4l-dev libva-dev libvulkan-dev libx11-dev libxcomposite-dev libxcursor-dev libxext-dev libxi-dev libxrandr-dev libxrender-dev libxt-dev libpango1.0-dev libicu-dev libharfbuzz-dev libgnutls28-dev libasound2-dev:i386 libavcodec-dev:i386 libcapi20-dev:i386 libdbus-1-dev:i386 libfontconfig1-dev:i386 libfreetype6-dev:i386 libgl1-mesa-dev:i386 libglu1-mesa-dev:i386 libgphoto2-dev:i386 libgsm1-dev:i386 libice-dev:i386 libjpeg-dev:i386 libkrb5-dev:i386 liblcms2-dev:i386 libldap2-dev:i386 libmpg123-dev:i386 libopenal-dev:i386 libosmesa6-dev:i386 libpng-dev:i386 libpulse-dev:i386 libsane-dev:i386 libssl-dev:i386 libudev-dev:i386 libv4l-dev:i386 libva-dev:i386 libvulkan-dev:i386 libx11-dev:i386 libxcomposite-dev:i386 libxcursor-dev:i386 libxext-dev:i386 libxi-dev:i386 libxrandr-dev:i386 libxrender-dev:i386 libxt-dev:i386 libgnutls28-dev:i386

mkdir proton-build
cd proton-build
../configure.sh --no-steam-runtime
# these are required by wine32
sudo apt install libsdl2-dev:i386 libcups2-dev:i386 libtiff-dev:i386 libxml2-dev:i386 libxslt-dev:i386 libicu-dev:i386 libgtk-3-dev:i386
# if the above command fails, add libmirclient-dev:i386, then run the below command
# sudo apt remove libmirclient-dev:amd64
# build faudio32, required by wine32
make faudio32
# build wine32
make wine32
# dxvk wants to make sure windows executables run
export PATH=$(realpath .)/obj-wine32:$PATH
export WINEPREFIX=$(realpath .)/temp-wineprefix32
# build dxvk
make dxvk32
rm -rf $WINEPREFIX
# build vrclient
make vrclient32
# clean up the mess and build wine64 and the rest of proton
sudo apt install libsdl2-dev libcups2-dev libtiff-dev libxml2-dev libxslt1-dev libicu-dev libgtk-3-dev
# only run the following command if the above command complains about libmirclient
# sudo apt remove libmirclient-dev:i386
make faudio64
make wine64
export PATH=$(realpath .)/obj-wine64:$PATH
export WINEPREFIX=$(realpath .)/temp-wineprefix64
make dxvk64
rm -rf $WINEPREFIX
# build the rest of proton
make vrclient64
make dist
# the output will be in the dist folder

# hopefully it worked
# to run:
# mkdir ~/.proton
# STEAM_COMPAT_DATA_PATH=$HOME/.proton ./proton run ~/.proton/pfx/drive_c/windows/notepad.exe
# the proton executable should be in proton-build/dist