[Feature] Support for Bazzite

[UneducatedChild]

Before Requesting

• I found no existing issue matching my feature request
• This request is related to Millennium, and not a request for a specific theme/addon

Describe the feature you'd like!

Support for bazzite as it is immutable and does let you write on system files, but just steam files (I think), I've seen discussions before about this topic and they got pretty as far as it being quite possible and they even highlighted the fact that all paths are changeable so that might be a good starting point.

I would love to see it fully implemented as alot of non-linux savvy people try out bazzite and having plugins and themes on steam are especially helpful and great to have!

Also this is technically similar to #475 but I believe this is about bazzite not all immutable systems as that seems like alot of variation to go thru.

Anything else?

posts mentioned:
#503
#475

[igor-tsiglyar]

Two problems need to be worked around on Bazzite as of Millennium 2.35.0:

---

Part 1 — Install to a writable location

The installer does sudo cp -r to /usr/lib/millennium, /usr/share/millennium, and /opt/python-i686-3.11.8 which are all on the read-only OSTree rootfs. The fix is to skip the system copy entirely and extract the release tarball directly to ~/.local/.

---

Part 2 — Fix hardcoded paths in the binaries

Even with files in ~/.local/, the binaries still reference the original system paths as C++ compile-time constants — environment variables have no effect on them. The fix is a binary patch to redirect those paths to /var/, backed by systemd-tmpfiles.d symlinks pointing to ~/.local/ — the idiomatic Bazzite mechanism for persistent /var/ entries that survive reboots.

Below is the script that does both pieces:

#!/usr/bin/bash
# Millennium installer/upgrader for Bazzite (immutable OS)
# Works around read-only /usr and /opt by:
#   1. Extracting the tarball directly to ~/.local/
#   2. Patching hardcoded paths in the .so files (/opt, /usr -> /var, same length)
#   3. Using systemd-tmpfiles to create /var/ symlinks on every boot

set -e

MILL_LIB="$HOME/.local/lib/millennium"
MILL_SHARE="$HOME/.local/share/millennium"
PYTHON_DIR="$HOME/.local/opt/python-i686-3.11.8"
STEAM_DIR="$HOME/.steam/steam"
GITHUB_ACCOUNT="SteamClientHomebrew/Millennium"

# ── 1. Fetch latest release tag ───────────────────────────────────────────────
echo "==> Fetching latest Millennium release..."
TAG=$(curl -fsSL "https://api.github.com/repos/${GITHUB_ACCOUNT}/releases" \
    -H 'Accept: application/vnd.github.v3+json' \
    | jq -r '[.[] | select(.prerelease == false)] | first | .tag_name')

if [[ -z "$TAG" || "$TAG" == "null" ]]; then
    echo "ERROR: Could not fetch release info"
    exit 1
fi

VERSION="${TAG#v}"
TARBALL_URL="https://github.com/${GITHUB_ACCOUNT}/releases/download/${TAG}/millennium-v${VERSION}-linux-x86_64.tar.gz"
echo "    Version: $VERSION"

# ── 2. Download and extract to ~/.local/ ──────────────────────────────────────
echo "==> Downloading tarball..."
TMPDIR=$(mktemp -d)
trap 'rm -rf "$TMPDIR"' EXIT

curl -fsSL "$TARBALL_URL" -o "$TMPDIR/millennium.tar.gz"

echo "==> Extracting to ~/.local/..."
mkdir -p "$MILL_LIB" "$MILL_SHARE" "$PYTHON_DIR"

# Extract to temp dir first, then copy to writable targets
tar -xzf "$TMPDIR/millennium.tar.gz" -C "$TMPDIR" --warning=no-timestamp 2>/dev/null || true

cp -r "$TMPDIR/usr/lib/millennium/."   "$MILL_LIB/"
cp -r "$TMPDIR/usr/share/millennium/." "$MILL_SHARE/"
cp -r "$TMPDIR/opt/python-i686-3.11.8/." "$PYTHON_DIR/"
chmod +x "$PYTHON_DIR/bin/python3.11"

# ── 3. Verify key files ───────────────────────────────────────────────────────
for f in \
    "$MILL_LIB/libmillennium_x86.so" \
    "$MILL_LIB/libmillennium_bootstrap_86x.so" \
    "$PYTHON_DIR/lib/libpython-3.11.8.so" \
    "$PYTHON_DIR/bin/python3.11"
do
    [[ -f "$f" ]] || { echo "ERROR: missing $f"; exit 1; }
done

# ── 4. Patch binaries (same-length string replacement, no relocation needed) ──
# /opt/python-i686-3.11.8  (23 chars) -> /var/python-i686-3.11.8  (23 chars)
# /usr/lib/millennium      (19 chars) -> /var/lib/millennium       (19 chars)
# /usr/share/millennium    (21 chars) -> /var/share/millennium     (21 chars)
echo "==> Patching binaries..."

perl -pi -e '
    s|/opt/python-i686-3\.11\.8|/var/python-i686-3.11.8|g;
    s|/usr/lib/millennium|/var/lib/millennium|g;
    s|/usr/share/millennium|/var/share/millennium|g;
' "$MILL_LIB/libmillennium_x86.so" \
  "$MILL_LIB/libmillennium_bootstrap_86x.so"

echo "    Verified patched paths:"
strings "$MILL_LIB/libmillennium_x86.so" \
    | grep -E "^/var/(python-i686|lib/millennium|share/millennium)" \
    | sed 's/^/      /'

# ── 5. Steam preload symlink ──────────────────────────────────────────────────
echo "==> Installing Steam preload hook..."
ln -sf "$MILL_LIB/libmillennium_bootstrap_86x.so" \
       "$STEAM_DIR/ubuntu12_32/libXtst.so.6"

# ── 6. systemd-tmpfiles for persistent /var/ symlinks ────────────────────────
echo "==> Writing /etc/tmpfiles.d/millennium.conf (requires sudo)..."
sudo tee /etc/tmpfiles.d/millennium.conf > /dev/null << EOF
# Millennium Steam mod framework — Bazzite immutable OS workaround
# Redirects hardcoded /var/ paths (patched from /opt/ and /usr/) to ~/.local installs
L /var/python-i686-3.11.8  -  -  -  -  $HOME/.local/opt/python-i686-3.11.8
L /var/lib/millennium      -  -  -  -  $HOME/.local/lib/millennium
L /var/share/millennium    -  -  -  -  $HOME/.local/share/millennium
EOF

sudo systemd-tmpfiles --create /etc/tmpfiles.d/millennium.conf

echo ""
echo "==> Symlinks:"
ls -la /var/python-i686-3.11.8 /var/lib/millennium /var/share/millennium

echo ""
echo "Done — Millennium $VERSION installed. Restart Steam to load it."

[ejalxndr]

https://github.com/SteamClientHomebrew/Millennium/blob/main/src/sys/env.cc

All paths are overridable by environment variables. if you start Steam with a environment var that shadows one Millennium uses, it will use yours instead. No patching.

[Zeglius]

Hi 👋. While is true that Bazzite has a read-only /usr, /usr/local is writable (being a symlink to /var/usrlocal) as so is /opt (symlink pointing to /var/opt, though this convention is weaker and might turn read-only in a non foreseeable future). Dropping that bit of information there, as personally feel like creating directories directly under /var is a bit messy.

[SephirothWS]

Just gonna voice my support for this request, having learned of the project through Brodie's Youtube video about the project. I run Bazzite, and was saddened to discover the read only filesystem was like "NAH BRO IT AIN'T HAPPENING". ... Sadge.

[igor-tsiglyar]

@shdwmtr great, thanks for the note, with that the script can fully do with just setting the correct env using tmpfiles:

  #!/usr/bin/bash
  # Millennium installer/upgrader for Bazzite (immutable OS)
  # Works around read-only /usr and /opt by:
  #   1. Extracting the tarball directly to ~/.local/
  #   2. Setting env vars so Millennium finds libs/assets in ~/.local/ (no binary patching)
  #   3. Using systemd-tmpfiles to create /opt/python-i686-3.11.8 symlink on every boot
  #      (/opt -> var/opt on OSTree, so the original RUNPATH works without patching)

  set -e

  MILL_LIB="$HOME/.local/lib/millennium"
  MILL_SHARE="$HOME/.local/share/millennium"
  PYTHON_DIR="$HOME/.local/opt/python-i686-3.11.8"
  STEAM_DIR="$HOME/.steam/steam"
  GITHUB_ACCOUNT="SteamClientHomebrew/Millennium"
  ENV_DIR="$HOME/.config/environment.d"

  # ── 1. Fetch latest release tag ───────────────────────────────────────────────
  echo "==> Fetching latest Millennium release..."
  TAG=$(curl -fsSL "https://api.github.com/repos/${GITHUB_ACCOUNT}/releases" \
      -H 'Accept: application/vnd.github.v3+json' \
      | jq -r '[.[] | select(.prerelease == false)] | first | .tag_name')

  if [[ -z "$TAG" || "$TAG" == "null" ]]; then
      echo "ERROR: Could not fetch release info"
      exit 1
  fi

  VERSION="${TAG#v}"
  TARBALL_URL="https://github.com/${GITHUB_ACCOUNT}/releases/download/${TAG}/millennium-v${VERSION}-linux-x86_64.tar.gz"
  echo "    Version: $VERSION"

  # ── 2. Download and extract to ~/.local/ ──────────────────────────────────────
  echo "==> Downloading tarball..."
  TMPDIR=$(mktemp -d)
  trap 'rm -rf "$TMPDIR"' EXIT

  curl -fsSL "$TARBALL_URL" -o "$TMPDIR/millennium.tar.gz"

  echo "==> Extracting to ~/.local/..."
  mkdir -p "$MILL_LIB" "$MILL_SHARE" "$PYTHON_DIR"

  tar -xzf "$TMPDIR/millennium.tar.gz" -C "$TMPDIR" --warning=no-timestamp 2>/dev/null || true

  cp -r "$TMPDIR/usr/lib/millennium/."   "$MILL_LIB/"
  cp -r "$TMPDIR/usr/share/millennium/." "$MILL_SHARE/"
  cp -r "$TMPDIR/opt/python-i686-3.11.8/." "$PYTHON_DIR/"
  chmod +x "$PYTHON_DIR/bin/python3.11"

  # ── 3. Verify key files ───────────────────────────────────────────────────────
  for f in \
      "$MILL_LIB/libmillennium_x86.so" \
      "$MILL_LIB/libmillennium_bootstrap_86x.so" \
      "$PYTHON_DIR/lib/libpython-3.11.8.so" \
      "$PYTHON_DIR/bin/python3.11"
  do
      [[ -f "$f" ]] || { echo "ERROR: missing $f"; exit 1; }
  done

  # ── 4. Write environment.d overrides ──────────────────────────────────────────
  # MILLENNIUM_RUNTIME_PATH: bootstrap reads getenv() in release builds (not compiled-in)
  # MILLENNIUM__SHIMS_PATH / MILLENNIUM__ASSETS_PATH: environment.cc respects pre-set vars
  echo "==> Writing $ENV_DIR/millennium.conf..."
  mkdir -p "$ENV_DIR"
  cat > "$ENV_DIR/millennium.conf" << EOF
  MILLENNIUM_RUNTIME_PATH=$HOME/.local/lib/millennium/libmillennium_x86.so
  MILLENNIUM__SHIMS_PATH=$HOME/.local/share/millennium/shims
  MILLENNIUM__ASSETS_PATH=$HOME/.local/share/millennium/assets
  MILLENNIUM__DATA_LIB=$HOME/.local/share/millennium
  EOF

  # ── 5. Steam preload symlink ──────────────────────────────────────────────────
  echo "==> Installing Steam preload hook..."
  ln -sf "$MILL_LIB/libmillennium_bootstrap_86x.so" \
         "$STEAM_DIR/ubuntu12_32/libXtst.so.6"

  # ── 6. systemd-tmpfiles for /opt/python symlink ───────────────────────────────
  # /opt -> var/opt on OSTree, so creating /var/opt/python-i686-3.11.8 satisfies
  # the RUNPATH baked into libmillennium_x86.so (/opt/python-i686-3.11.8/lib)
  echo "==> Writing /etc/tmpfiles.d/millennium.conf (requires sudo)..."
  sudo tee /etc/tmpfiles.d/millennium.conf > /dev/null << EOF
  # Millennium Steam mod framework — Bazzite immutable OS workaround
  # /opt -> var/opt on OSTree; this satisfies the RUNPATH in libmillennium_x86.so
  L /var/opt/python-i686-3.11.8  -  -  -  -  $HOME/.local/opt/python-i686-3.11.8
  EOF

  sudo systemd-tmpfiles --create /etc/tmpfiles.d/millennium.conf

  echo ""
  echo "==> Symlink:"
  ls -la /opt/python-i686-3.11.8

  echo ""
  echo "Done — Millennium $VERSION installed."
  echo "Log out and back in (or reboot) for environment.d vars to take effect, then restart Steam."

[hidnight]

It does work on Bazzite but I had to remove leading blanks in the script otherwise it gets mad on file writing steps. I also replaced << EOF with <<EOF.

@shdwmtr great, thanks for the note, with that the script can fully do with just setting the correct env using tmpfiles:

[hidnight]

Strange. The exact same script failed today with
cp: cannot stat '/tmp/tmp.3mLQtYT57G/usr/share/millennium/.': No such file or directory
I changed
mkdir -p "$MILL_LIB" "$MILL_SHARE" "$PYTHON_DIR"
to
mkdir -p "$MILL_LIB" "$MILL_SHARE" "$PYTHON_DIR" "$TMPDIR/usr/lib/millennium/." "$TMPDIR/usr/share/millennium/." "$TMPDIR/opt/python-i686-3.11.8/."
Seemed to fix it.

[hidnight]

Also trap 'rm -rf "$TMPDIR"' EXIT should be guarded with checks to prevent accidental rm -rf /

[hidnight]

For whatever reason files ~/.local/lib/millennium/libmillennium_luavm_x86 and ~/.local/lib/millennium/libmillennium_pvs64 lost exec permission and prevented steamwebhelper from running.

[Mercvre80]

bazzite stable, 44.20260515
I use the latest script that u/igor-tsiglyar provided, with the latest change from @hidnight
just like you, hidnight, I got a permission issue when launching steam
what solved it was running the script, log in/out, trying to execute /tmp/.millennium-pv-OvSiOx/bin/pressure-vessel-unruntime
downloaded/installed themes are missing, but now millenium works

all of this may be because of the 3.1.0 update ?
this projet is very good, it's just a bit complicated to get it working/to update it on bazzite

[Shellke]

I couldn't get this to work and went ahead and modified the official install script myself and added environment variables manually, seems to be working fine for now.

~/.config/environment.d/milllennium.conf

MILLENNIUM_RUNTIME_PATH=$HOME/.millennium/usr/lib/millennium/libmillennium_x86.so
MILLENNIUM__DATA_LIB=$HOME/.millennium/usr/share/millennium
MILLENNIUM__ASSETS_PATH=$HOME/.millennium/usr/share/millennium/assets
MILLENNIUM__SHIMS_PATH=$HOME/.millennium/usr/share/millennium/shims

And a modified install script:

#!/usr/bin/env bash

# ==================================================
#   _____ _ _ _             _
#  |     |_| | |___ ___ ___|_|_ _ _____
#  | | | | | | | -_|   |   | | | |     |
#  |_|_|_|_|_|_|___|_|_|_|_|_|___|_|_|_|
#
# ==================================================

# Copyright (c) 2026 Project Millennium

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# https://github.com/SteamClientHomebrew/Millennium/blob/main/scripts/install.sh

readonly GITHUB_ACCOUNT="SteamClientHomebrew/Millennium"
readonly RELEASES_URI="https://api.github.com/repos/${GITHUB_ACCOUNT}/releases"
readonly DOWNLOAD_URI="https://github.com/${GITHUB_ACCOUNT}/releases/download"
readonly NIGHTLY_URI="https://nightly.link/${GITHUB_ACCOUNT}/actions/runs"
readonly INSTALL_DIR="/tmp/millennium"
DRY_RUN=0
RUN_ID=""
BETA=0
YES=0

log() { printf "%b\n" "$1"; }
warn() { printf "\033[1;33m%b\033[0m\n" "$1"; }
is_root() { [ "$(id -u)" -eq 0 ]; }
format_size() {
    echo "$1" | awk '{ split("B KB MB GB TB PB", v); s=1; while ($1 > 1024) { $1 /= 1024; s++ } printf "%.2f %s\n", $1, v[s] }'
}

verify_platform() {
    case $(uname -sm) in
        "Linux x86_64") echo "linux-x86_64" ;;
        *) log "Unsupported platform $(uname -sm). x86_64 is the only available platform."; exit 1 ;;
    esac
}

check_dependencies() {
    log "resolving dependencies..."
    local deps=(curl tar jq sudo)
    [ -n "${RUN_ID}" ] && deps+=(unzip)
    for cmd in "${deps[@]}"; do
        command -v "${cmd}" >/dev/null || {
            log "${cmd} isn't installed. Install it from your package manager." >&2
            exit 1
        }
    done
}

is_debian_based() {
    [ -f /etc/os-release ] || return 1
    local id id_like
    id=$(. /etc/os-release && echo "${ID:-}")
    id_like=$(. /etc/os-release && echo "${ID_LIKE:-}")
    case "${id} ${id_like}" in
        *debian*|*ubuntu*) return 0 ;;
        *) return 1 ;;
    esac
}

check_ssl_i386() {
    is_debian_based || return 0
    dpkg -s libssl-dev:i386 &>/dev/null && return 0
    warn "missing dependency: libssl-dev:i386"
    warn "  install it with: sudo dpkg --add-architecture i386 && sudo apt-get update && sudo apt-get install libssl-dev:i386"
    exit 1
}

fetch_release_info() {
    local page=1 per_page=100 response tag size
    local filter
    [ "${BETA}" -eq 1 ] && filter='.[]' || filter='.[] | select(.prerelease == false)'

    while :; do
        response=$(curl -fsSL \
            -H 'Accept: application/vnd.github.v3+json' \
            "${RELEASES_URI}?per_page=${per_page}&page=${page}") || return 1

        [ "$(echo "${response}" | jq 'length')" -eq 0 ] && break

        tag=$(echo "${response}" | jq -r "${filter} | .tag_name" | head -n1)

        if [ -n "${tag}" ] && [ "${tag}" != "null" ]; then
            size=$(echo "${response}" | jq -r "
                .[]
                | select(.tag_name == \"${tag}\")
                | .assets[]
                | select(.name == \"millennium-v${tag#v}-${target}.tar.gz\")
                | .size
            ")
            echo "${tag#v}:${size:-0}"
            return 0
        fi

        page=$((page + 1))
    done

    log "No releases found."
    return 1
}

fetch_artifact_from_run() {
    local run_id="$1"
    local dest_dir="$2"
    local zip_url="${NIGHTLY_URI}/${run_id}/millennium-linux.zip"
    local zip_file="${dest_dir}.zip"

    mkdir -p "${dest_dir}"
    log "downloading from nightly.link (no auth required)..."
    if ! curl --fail --location --output "${zip_file}" "${zip_url}"; then
        log "Download failed. Check that run ${run_id} exists, is from a public repo, and has a 'millennium-linux' artifact."
        return 1
    fi

    unzip -q "${zip_file}" -d "${dest_dir}"
    rm -f "${zip_file}"
}

confirm_installation() {
    [ "${YES}" -eq 1 ] && return 0
    echo -e "\n:: Proceed with installation? [Y/n] \c"
    read -r proceed </dev/tty
    case "${proceed}" in
        [Nn]*) exit 1 ;;
        *) return 0 ;;
    esac
}

download_package() {
    local url="$1"
    local dest="$2"
    if ! curl --fail --location --output "${dest}" "${url}"; then
        log "Download failed for ${url}"
        return 1
    fi
}

extract_package() {
    local tar_file="$1"
    local extract_dir="$2"
    mkdir -p "${extract_dir}"
    tar xzf "${tar_file}" -C "${extract_dir}"
}

install_millennium() {
    local extract_path="$1"

    if [ "${DRY_RUN}" -eq 0 ]; then
        cp -r "${extract_path}"/* $HOME/.millennium/ || true
    else
        log "[DRY RUN] Would copy files from ${extract_path} to /"
    fi
}

post_install() {
    chmod +x $HOME/.millennium/usr/lib/millennium/libmillennium_pvs64 2>/dev/null || true
    chmod +x $HOME/.millennium/usr/lib/millennium/libmillennium_luavm_x86 2>/dev/null || true

    log "installing for '${USER}'"

    beta_file="${HOME}/.steam/steam/package/beta"

    # make sure to force steam stable for the first install.
    # if the user wants beta they can set it after install.
    # normally its fine, but many users forget they have it enabled on first install,
    # and then face issues.
    if [ -f "${beta_file}" ]; then
        log "removing beta '$(cat "${beta_file}")' in favor for stable."
        rm "${beta_file}"
    fi

    # create symlinks for millenniums preload bootstraps.
    mkdir -p "${HOME}/.steam/steam/ubuntu12_32" "${HOME}/.steam/steam/ubuntu12_64"
    ln -sf $HOME/.millennium/usr/lib/millennium/libmillennium_bootstrap_x86.so   "${HOME}/.steam/steam/ubuntu12_32/libXtst.so.6"
    ln -sf $HOME/.millennium/usr/lib/millennium/libmillennium_bootstrap_hhx64.so "${HOME}/.steam/steam/ubuntu12_64/libXtst.so.6"
    ln -sf $HOME/.millennium/usr/lib/millennium/libmillennium_hhx64.so           "${HOME}/.steam/steam/ubuntu12_64/libmillennium_hhx64.so"
}

cleanup() {
    local dir="$1"
    log "cleaning up..."
    rm -rf "${dir}"
}

main() {
    local target release_info tag size download_uri install_dir extract_path tar_file

    # Parse arguments
    while [ $# -gt 0 ]; do
        case "$1" in
            --dry-run)    DRY_RUN=1 ;;
            --beta)       BETA=1 ;;
            --yes)        YES=1 ;;
            --run-id)     shift; RUN_ID="$1" ;;
            --run-id=*)   RUN_ID="${1#*=}" ;;
        esac
        shift
    done

    if is_root; then
        log "Do not run this script as root!"
        log "aborting installation..."
        exit
    fi

    target=$(verify_platform)
    check_dependencies
    check_ssl_i386

    install_dir="${DRY_RUN:+./dry-run}"
    install_dir="${install_dir:-${INSTALL_DIR}}"
    extract_path="${install_dir}/files"

    rm -rf "${install_dir}"
    mkdir -p "${install_dir}"

    if [ -n "${RUN_ID}" ]; then
        log "\nInstalling from GitHub Actions run ${RUN_ID}\n"
        confirm_installation
        log "receiving packages..."

        log "(1/2) Downloading and unpacking artifact from run ${RUN_ID}..."
        fetch_artifact_from_run "${RUN_ID}" "${extract_path}"
        log "(2/2) Installing millennium..."
        install_millennium "${extract_path}"
    else
        release_info=$(fetch_release_info)
        tag="${release_info%%:*}"
        size=$(format_size "${release_info##*:}")

        install_size_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.installsize"
        download_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.tar.gz"
        sha256_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.sha256"

        sha256digest=$(curl -sL "${sha256_uri}")
        installed_size=$(format_size "$(curl -sL "${install_size_uri}")")

        log "\nPackages (1) millennium@${tag}-x86_64\n"
        log "Total Download Size:  $(printf "%10s\n" "${size}")"
        log "Total Installed Size: $(printf "%10s\n" "${installed_size}")"

        confirm_installation
        log "receiving packages..."

        tar_file="${install_dir}/millennium-v${tag}-${target}.tar.gz"

        log "(1/4) Downloading millennium-v${tag}-${target}.tar.gz..."
        download_package "${download_uri}" "${tar_file}"
        log "(2/4) Verifying checksums..."
        if (cd "${install_dir}" && echo "${sha256digest}" | sha256sum -c --status); then
            echo -ne "\033[1A"
            log "(2/4) Verifying checksums... OK"
        else
            log "(2/4) Verifying checksums... FAILED"
        fi
        log "(3/4) Unpacking millennium-v${tag}-${target}.tar.gz..."
        extract_package "${tar_file}" "${extract_path}"
        log "(4/4) Installing millennium..."
        install_millennium "${extract_path}"
    fi

    log ":: Running post-install scripts..."
    log "(1/1) Setting up shared object preloader hook..."
    post_install

    cleanup "${install_dir}"

    log "done.\n"
    log "You can now start Steam."
    log "https://docs.steambrew.app/users/installing#post-installation."
}

main "$@"

[HitWithSpader]

Not sure if I'm meant to actually use this script, but Millennium did install, but failed to load:

[59:09.029] BOOTSTRAP-INFO Setting up proxy hooks...
[59:09.029] BOOTSTRAP-INFO Bootstrap library loaded successfully. Using Millennium library at: /usr/lib/millennium/libmillennium_x86.so
[59:09.029] BOOTSTRAP-ERROR Failed to dlopen /usr/lib/millennium/libmillennium_x86.so: /usr/lib/millennium/libmillennium_x86.so: cannot open shared object file: No such file or directory
[59:09.029] BOOTSTRAP-ERROR Failed to load Millennium...

I did make a file at: ~/.config/environment.d/milllennium.conf which I corrected to ~/.config/environment.d/millennium.conf but it didn't seem to do anything.

[Shellke]

Have to use the modified script to install everything in home directory and have symlinks point there.
Either run it, or reboot after setting up environment.d, or both.
Error implies it tries to either follow official symlink that has nothing installed in read-only directory that won't persist on bazzite, or maybe default environment var does the same because environment.d didn't apply.

The name of environment.d config file shouldn't matter, but I made a typo there, aye.
I could also probably just copy from extracted_path/usr/ to home/.local/ instead of copying the whole archive to .millenium, but it didn't occur to me back then.

[HitWithSpader]

Yeah I needed to reboot thanks

[source-guilherme]

Reminder to setup the millennium.conf for it to work. Thanks!

[Shellke]

Remade the previous edit of official install.sh, environment.d is now handled by script and ~/.local is used instead of ~/.millenium/usr

Changes from official installer:

Modified installer:

# ==================================================
#   _____ _ _ _             _
#  |     |_| | |___ ___ ___|_|_ _ _____
#  | | | | | | | -_|   |   | | | |     |
#  |_|_|_|_|_|_|___|_|_|_|_|_|___|_|_|_|
#
# ==================================================

# Copyright (c) 2026 Project Millennium

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# https://github.com/SteamClientHomebrew/Millennium/blob/main/scripts/install.sh

readonly GITHUB_ACCOUNT="SteamClientHomebrew/Millennium"
readonly RELEASES_URI="https://api.github.com/repos/${GITHUB_ACCOUNT}/releases"
readonly DOWNLOAD_URI="https://github.com/${GITHUB_ACCOUNT}/releases/download"
readonly NIGHTLY_URI="https://nightly.link/${GITHUB_ACCOUNT}/actions/runs"
readonly INSTALL_DIR="/tmp/millennium"
DRY_RUN=0
RUN_ID=""
BETA=0
YES=0

log() { printf "%b\n" "$1"; }
warn() { printf "\033[1;33m%b\033[0m\n" "$1"; }
is_root() { [ "$(id -u)" -eq 0 ]; }
format_size() {
    echo "$1" | awk '{ split("B KB MB GB TB PB", v); s=1; while ($1 > 1024) { $1 /= 1024; s++ } printf "%.2f %s\n", $1, v[s] }'
}

verify_platform() {
    case $(uname -sm) in
        "Linux x86_64") echo "linux-x86_64" ;;
        *) log "Unsupported platform $(uname -sm). x86_64 is the only available platform."; exit 1 ;;
    esac
}

check_dependencies() {
    log "resolving dependencies..."
    local deps=(curl tar jq sudo)
    [ -n "${RUN_ID}" ] && deps+=(unzip)
    for cmd in "${deps[@]}"; do
        command -v "${cmd}" >/dev/null || {
            log "${cmd} isn't installed. Install it from your package manager." >&2
            exit 1
        }
    done
}

is_debian_based() {
    [ -f /etc/os-release ] || return 1
    local id id_like
    id=$(. /etc/os-release && echo "${ID:-}")
    id_like=$(. /etc/os-release && echo "${ID_LIKE:-}")
    case "${id} ${id_like}" in
        *debian*|*ubuntu*) return 0 ;;
        *) return 1 ;;
    esac
}

check_ssl_i386() {
    is_debian_based || return 0
    dpkg -s libssl-dev:i386 &>/dev/null && return 0
    warn "missing dependency: libssl-dev:i386"
    warn "  install it with: sudo dpkg --add-architecture i386 && sudo apt-get update && sudo apt-get install libssl-dev:i386"
    exit 1
}

fetch_release_info() {
    local page=1 per_page=100 response tag size
    local filter
    [ "${BETA}" -eq 1 ] && filter='.[]' || filter='.[] | select(.prerelease == false)'

    while :; do
        response=$(curl -fsSL \
            -H 'Accept: application/vnd.github.v3+json' \
            "${RELEASES_URI}?per_page=${per_page}&page=${page}") || return 1

        [ "$(echo "${response}" | jq 'length')" -eq 0 ] && break

        tag=$(echo "${response}" | jq -r "${filter} | .tag_name" | head -n1)

        if [ -n "${tag}" ] && [ "${tag}" != "null" ]; then
            size=$(echo "${response}" | jq -r "
                .[]
                | select(.tag_name == \"${tag}\")
                | .assets[]
                | select(.name == \"millennium-v${tag#v}-${target}.tar.gz\")
                | .size
            ")
            echo "${tag#v}:${size:-0}"
            return 0
        fi

        page=$((page + 1))
    done

    log "No releases found."
    return 1
}

fetch_artifact_from_run() {
    local run_id="$1"
    local dest_dir="$2"
    local zip_url="${NIGHTLY_URI}/${run_id}/millennium-linux.zip"
    local zip_file="${dest_dir}.zip"

    mkdir -p "${dest_dir}"
    log "downloading from nightly.link (no auth required)..."
    if ! curl --fail --location --output "${zip_file}" "${zip_url}"; then
        log "Download failed. Check that run ${run_id} exists, is from a public repo, and has a 'millennium-linux' artifact."
        return 1
    fi

    unzip -q "${zip_file}" -d "${dest_dir}"
    rm -f "${zip_file}"
}

confirm_installation() {
    [ "${YES}" -eq 1 ] && return 0
    echo -e "\n:: Proceed with installation? [Y/n] \c"
    read -r proceed </dev/tty
    case "${proceed}" in
        [Nn]*) exit 1 ;;
        *) return 0 ;;
    esac
}

download_package() {
    local url="$1"
    local dest="$2"
    if ! curl --fail --location --output "${dest}" "${url}"; then
        log "Download failed for ${url}"
        return 1
    fi
}

extract_package() {
    local tar_file="$1"
    local extract_dir="$2"
    mkdir -p "${extract_dir}"
    tar xzf "${tar_file}" -C "${extract_dir}"
}

install_millennium() {
    local extract_path="$1"

    if [ "${DRY_RUN}" -eq 0 ]; then
        cp -r "${extract_path}"/usr/* $HOME/.local/ || true
    else
        log "[DRY RUN] Would copy files from ${extract_path} to /"
    fi
}

post_install() {
    chmod +x $HOME/.local/lib/millennium/libmillennium_pvs64 2>/dev/null || true
    chmod +x $HOME/.local/lib/millennium/libmillennium_luavm_x86 2>/dev/null || true

    log "installing for '${USER}'"

    beta_file="${HOME}/.steam/steam/package/beta"

    # make sure to force steam stable for the first install.
    # if the user wants beta they can set it after install.
    # normally its fine, but many users forget they have it enabled on first install,
    # and then face issues.
    if [ -f "${beta_file}" ]; then
        log "removing beta '$(cat "${beta_file}")' in favor for stable."
        rm "${beta_file}"
    fi

    # create symlinks for millenniums preload bootstraps.
    mkdir -p "${HOME}/.steam/steam/ubuntu12_32" "${HOME}/.steam/steam/ubuntu12_64"
    ln -sf $HOME/.local/lib/millennium/libmillennium_bootstrap_x86.so   "${HOME}/.steam/steam/ubuntu12_32/libXtst.so.6"
    ln -sf $HOME/.local/lib/millennium/libmillennium_bootstrap_hhx64.so "${HOME}/.steam/steam/ubuntu12_64/libXtst.so.6"
    ln -sf $HOME/.local/lib/millennium/libmillennium_hhx64.so           "${HOME}/.steam/steam/ubuntu12_64/libmillennium_hhx64.so"

    echo "==> Writing $HOME/.config/environment.d/millennium.conf..."
    cat > "$HOME/.config/environment.d/millennium.conf" <<EOF
MILLENNIUM_RUNTIME_PATH=$HOME/.local/lib/millennium/libmillennium_x86.so
MILLENNIUM__DATA_LIB=$HOME/.local/share/millennium
MILLENNIUM__ASSETS_PATH=$HOME/.local/share/millennium/assets
MILLENNIUM__SHIMS_PATH=$HOME/.local/share/millennium/shims
EOF
}

cleanup() {
    local dir="$1"
    log "cleaning up..."
    rm -rf "${dir}"
}

main() {
    local target release_info tag size download_uri install_dir extract_path tar_file

    # Parse arguments
    while [ $# -gt 0 ]; do
        case "$1" in
            --dry-run)    DRY_RUN=1 ;;
            --beta)       BETA=1 ;;
            --yes)        YES=1 ;;
            --run-id)     shift; RUN_ID="$1" ;;
            --run-id=*)   RUN_ID="${1#*=}" ;;
        esac
        shift
    done

    if is_root; then
        log "Do not run this script as root!"
        log "aborting installation..."
        exit
    fi

    target=$(verify_platform)
    check_dependencies
    check_ssl_i386

    install_dir="${DRY_RUN:+./dry-run}"
    install_dir="${install_dir:-${INSTALL_DIR}}"
    extract_path="${install_dir}/files"

    rm -rf "${install_dir}"
    mkdir -p "${install_dir}"

    if [ -n "${RUN_ID}" ]; then
        log "\nInstalling from GitHub Actions run ${RUN_ID}\n"
        confirm_installation
        log "receiving packages..."

        log "(1/2) Downloading and unpacking artifact from run ${RUN_ID}..."
        fetch_artifact_from_run "${RUN_ID}" "${extract_path}"
        log "(2/2) Installing millennium..."
        install_millennium "${extract_path}"
    else
        release_info=$(fetch_release_info)
        tag="${release_info%%:*}"
        size=$(format_size "${release_info##*:}")

        install_size_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.installsize"
        download_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.tar.gz"
        sha256_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.sha256"

        sha256digest=$(curl -sL "${sha256_uri}")
        installed_size=$(format_size "$(curl -sL "${install_size_uri}")")

        log "\nPackages (1) millennium@${tag}-x86_64\n"
        log "Total Download Size:  $(printf "%10s\n" "${size}")"
        log "Total Installed Size: $(printf "%10s\n" "${installed_size}")"

        confirm_installation
        log "receiving packages..."

        tar_file="${install_dir}/millennium-v${tag}-${target}.tar.gz"

        log "(1/4) Downloading millennium-v${tag}-${target}.tar.gz..."
        download_package "${download_uri}" "${tar_file}"
        log "(2/4) Verifying checksums..."
        if (cd "${install_dir}" && echo "${sha256digest}" | sha256sum -c --status); then
            echo -ne "\033[1A"
            log "(2/4) Verifying checksums... OK"
        else
            log "(2/4) Verifying checksums... FAILED"
        fi
        log "(3/4) Unpacking millennium-v${tag}-${target}.tar.gz..."
        extract_package "${tar_file}" "${extract_path}"
        log "(4/4) Installing millennium..."
        install_millennium "${extract_path}"
    fi

    log ":: Running post-install scripts..."
    log "(1/1) Setting up shared object preloader hook..."
    post_install

    cleanup "${install_dir}"

    log "done.\n"
    log "Reboot before starting Steam."
    log "https://docs.steambrew.app/users/installing#post-installation."
}

main "$@"

[der-siebte-schatten]

Works great for me on the latest version of Bazzite, many thanks!

[LunRos]

Remade the previous edit of official install.sh, environment.d is now handled by script and ~/.local is used instead of ~/.millenium/usr

The script fails if /home/<username>/.config/environment.d doesn't already exist.

Added mkdir -p "$HOME/.config/environment.d"

# ==================================================
#   _____ _ _ _             _
#  |     |_| | |___ ___ ___|_|_ _ _____
#  | | | | | | | -_|   |   | | | |     |
#  |_|_|_|_|_|_|___|_|_|_|_|_|___|_|_|_|
#
# ==================================================

# Copyright (c) 2026 Project Millennium

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# https://github.com/SteamClientHomebrew/Millennium/blob/main/scripts/install.sh

readonly GITHUB_ACCOUNT="SteamClientHomebrew/Millennium"
readonly RELEASES_URI="https://api.github.com/repos/${GITHUB_ACCOUNT}/releases"
readonly DOWNLOAD_URI="https://github.com/${GITHUB_ACCOUNT}/releases/download"
readonly NIGHTLY_URI="https://nightly.link/${GITHUB_ACCOUNT}/actions/runs"
readonly INSTALL_DIR="/tmp/millennium"
DRY_RUN=0
RUN_ID=""
BETA=0
YES=0

log() { printf "%b\n" "$1"; }
warn() { printf "\033[1;33m%b\033[0m\n" "$1"; }
is_root() { [ "$(id -u)" -eq 0 ]; }
format_size() {
    echo "$1" | awk '{ split("B KB MB GB TB PB", v); s=1; while ($1 > 1024) { $1 /= 1024; s++ } printf "%.2f %s\n", $1, v[s] }'
}

verify_platform() {
    case $(uname -sm) in
        "Linux x86_64") echo "linux-x86_64" ;;
        *) log "Unsupported platform $(uname -sm). x86_64 is the only available platform."; exit 1 ;;
    esac
}

check_dependencies() {
    log "resolving dependencies..."
    local deps=(curl tar jq sudo)
    [ -n "${RUN_ID}" ] && deps+=(unzip)
    for cmd in "${deps[@]}"; do
        command -v "${cmd}" >/dev/null || {
            log "${cmd} isn't installed. Install it from your package manager." >&2
            exit 1
        }
    done
}

is_debian_based() {
    [ -f /etc/os-release ] || return 1
    local id id_like
    id=$(. /etc/os-release && echo "${ID:-}")
    id_like=$(. /etc/os-release && echo "${ID_LIKE:-}")
    case "${id} ${id_like}" in
        *debian*|*ubuntu*) return 0 ;;
        *) return 1 ;;
    esac
}

check_ssl_i386() {
    is_debian_based || return 0
    dpkg -s libssl-dev:i386 &>/dev/null && return 0
    warn "missing dependency: libssl-dev:i386"
    warn "  install it with: sudo dpkg --add-architecture i386 && sudo apt-get update && sudo apt-get install libssl-dev:i386"
    exit 1
}

fetch_release_info() {
    local page=1 per_page=100 response tag size
    local filter
    [ "${BETA}" -eq 1 ] && filter='.[]' || filter='.[] | select(.prerelease == false)'

    while :; do
        response=$(curl -fsSL \
            -H 'Accept: application/vnd.github.v3+json' \
            "${RELEASES_URI}?per_page=${per_page}&page=${page}") || return 1

        [ "$(echo "${response}" | jq 'length')" -eq 0 ] && break

        tag=$(echo "${response}" | jq -r "${filter} | .tag_name" | head -n1)

        if [ -n "${tag}" ] && [ "${tag}" != "null" ]; then
            size=$(echo "${response}" | jq -r "
                .[]
                | select(.tag_name == \"${tag}\")
                | .assets[]
                | select(.name == \"millennium-v${tag#v}-${target}.tar.gz\")
                | .size
            ")
            echo "${tag#v}:${size:-0}"
            return 0
        fi

        page=$((page + 1))
    done

    log "No releases found."
    return 1
}

fetch_artifact_from_run() {
    local run_id="$1"
    local dest_dir="$2"
    local zip_url="${NIGHTLY_URI}/${run_id}/millennium-linux.zip"
    local zip_file="${dest_dir}.zip"

    mkdir -p "${dest_dir}"
    log "downloading from nightly.link (no auth required)..."
    if ! curl --fail --location --output "${zip_file}" "${zip_url}"; then
        log "Download failed. Check that run ${run_id} exists, is from a public repo, and has a 'millennium-linux' artifact."
        return 1
    fi

    unzip -q "${zip_file}" -d "${dest_dir}"
    rm -f "${zip_file}"
}

confirm_installation() {
    [ "${YES}" -eq 1 ] && return 0
    echo -e "\n:: Proceed with installation? [Y/n] \c"
    read -r proceed </dev/tty
    case "${proceed}" in
        [Nn]*) exit 1 ;;
        *) return 0 ;;
    esac
}

download_package() {
    local url="$1"
    local dest="$2"
    if ! curl --fail --location --output "${dest}" "${url}"; then
        log "Download failed for ${url}"
        return 1
    fi
}

extract_package() {
    local tar_file="$1"
    local extract_dir="$2"
    mkdir -p "${extract_dir}"
    tar xzf "${tar_file}" -C "${extract_dir}"
}

install_millennium() {
    local extract_path="$1"

    if [ "${DRY_RUN}" -eq 0 ]; then
        cp -r "${extract_path}"/usr/* $HOME/.local/ || true
    else
        log "[DRY RUN] Would copy files from ${extract_path} to /"
    fi
}

post_install() {
    chmod +x $HOME/.local/lib/millennium/libmillennium_pvs64 2>/dev/null || true
    chmod +x $HOME/.local/lib/millennium/libmillennium_luavm_x86 2>/dev/null || true

    log "installing for '${USER}'"

    beta_file="${HOME}/.steam/steam/package/beta"

    # make sure to force steam stable for the first install.
    # if the user wants beta they can set it after install.
    # normally its fine, but many users forget they have it enabled on first install,
    # and then face issues.
    if [ -f "${beta_file}" ]; then
        log "removing beta '$(cat "${beta_file}")' in favor for stable."
        rm "${beta_file}"
    fi

    # create symlinks for millenniums preload bootstraps.
    mkdir -p "${HOME}/.steam/steam/ubuntu12_32" "${HOME}/.steam/steam/ubuntu12_64"
    ln -sf $HOME/.local/lib/millennium/libmillennium_bootstrap_x86.so   "${HOME}/.steam/steam/ubuntu12_32/libXtst.so.6"
    ln -sf $HOME/.local/lib/millennium/libmillennium_bootstrap_hhx64.so "${HOME}/.steam/steam/ubuntu12_64/libXtst.so.6"
    ln -sf $HOME/.local/lib/millennium/libmillennium_hhx64.so           "${HOME}/.steam/steam/ubuntu12_64/libmillennium_hhx64.so"

    # ensure the parent directory exists
    mkdir -p "$HOME/.config/environment.d"

    echo "==> Writing $HOME/.config/environment.d/millennium.conf..."
    cat > "$HOME/.config/environment.d/millennium.conf" <<EOF
MILLENNIUM_RUNTIME_PATH=$HOME/.local/lib/millennium/libmillennium_x86.so
MILLENNIUM__DATA_LIB=$HOME/.local/share/millennium
MILLENNIUM__ASSETS_PATH=$HOME/.local/share/millennium/assets
MILLENNIUM__SHIMS_PATH=$HOME/.local/share/millennium/shims
EOF
}

cleanup() {
    local dir="$1"
    log "cleaning up..."
    rm -rf "${dir}"
}

main() {
    local target release_info tag size download_uri install_dir extract_path tar_file

    # Parse arguments
    while [ $# -gt 0 ]; do
        case "$1" in
            --dry-run)    DRY_RUN=1 ;;
            --beta)       BETA=1 ;;
            --yes)        YES=1 ;;
            --run-id)     shift; RUN_ID="$1" ;;
            --run-id=*)   RUN_ID="${1#*=}" ;;
        esac
        shift
    done

    if is_root; then
        log "Do not run this script as root!"
        log "aborting installation..."
        exit
    fi

    target=$(verify_platform)
    check_dependencies
    check_ssl_i386

    install_dir="${DRY_RUN:+./dry-run}"
    install_dir="${install_dir:-${INSTALL_DIR}}"
    extract_path="${install_dir}/files"

    rm -rf "${install_dir}"
    mkdir -p "${install_dir}"

    if [ -n "${RUN_ID}" ]; then
        log "\nInstalling from GitHub Actions run ${RUN_ID}\n"
        confirm_installation
        log "receiving packages..."

        log "(1/2) Downloading and unpacking artifact from run ${RUN_ID}..."
        fetch_artifact_from_run "${RUN_ID}" "${extract_path}"
        log "(2/2) Installing millennium..."
        install_millennium "${extract_path}"
    else
        release_info=$(fetch_release_info)
        tag="${release_info%%:*}"
        size=$(format_size "${release_info##*:}")

        install_size_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.installsize"
        download_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.tar.gz"
        sha256_uri="${DOWNLOAD_URI}/v${tag}/millennium-v${tag}-${target}.sha256"

        sha256digest=$(curl -sL "${sha256_uri}")
        installed_size=$(format_size "$(curl -sL "${install_size_uri}")")

        log "\nPackages (1) millennium@${tag}-x86_64\n"
        log "Total Download Size:  $(printf "%10s\n" "${size}")"
        log "Total Installed Size: $(printf "%10s\n" "${installed_size}")"

        confirm_installation
        log "receiving packages..."

        tar_file="${install_dir}/millennium-v${tag}-${target}.tar.gz"

        log "(1/4) Downloading millennium-v${tag}-${target}.tar.gz..."
        download_package "${download_uri}" "${tar_file}"
        log "(2/4) Verifying checksums..."
        if (cd "${install_dir}" && echo "${sha256digest}" | sha256sum -c --status); then
            echo -ne "\033[1A"
            log "(2/4) Verifying checksums... OK"
        else
            log "(2/4) Verifying checksums... FAILED"
        fi
        log "(3/4) Unpacking millennium-v${tag}-${target}.tar.gz..."
        extract_package "${tar_file}" "${extract_path}"
        log "(4/4) Installing millennium..."
        install_millennium "${extract_path}"
    fi

    log ":: Running post-install scripts..."
    log "(1/1) Setting up shared object preloader hook..."
    post_install

    cleanup "${install_dir}"

    log "done.\n"
    log "Reboot before starting Steam."
    log "https://docs.steambrew.app/users/installing#post-installation."
}

main "$@"

[ViniciusMS-POA]

Has anyone managed to get Millennium to work on Bazzite?

[RingBandit]

after installation it should be available from streams menu on the top. There should be a new Millennium Entry there now.

[ViniciusMS-POA]

I figured out the problem.
SteamRT3 was enabled on my Steam.
You have to disable this feature...

[RingBandit]

oh okay, what's SteamRT3? like the beta enabled in settings or what?

[Shellke]

Yeah Millennium doesn't work with Steam 64 bit beta yet.

[JankyMouse]

#983

[ethembeldagli]

I turned the approach from this thread into an installer that handles Bazzite's read-only /usr and keeps Decky working:

curl -fsSL https://raw.githubusercontent.com/ethembeldagli/millennium-bazzite/main/install.sh | sh

• Installs the official Millennium release (SHA-256 checked) into ~/.local/lib/millennium. No sudo, nothing in /usr, and it survives Bazzite updates.
• Sets MILLENNIUM_RUNTIME_PATH through ~/.config/environment.d. It restarts Steam and checks that Millennium actually loaded, so there's no reboot. Log out once later so it also loads when you open Steam yourself.
• Decky keeps working. Millennium deletes .cef-enable-remote-debugging, and Decky blanks the Millennium settings page ([Bug] Select menu Steam>Millenium doesn't #472). So by default Millennium loads in Desktop Mode and Game Mode stays stock with Decky. You can turn Millennium on in Game Mode too if you don't use Decky.
• Run the same command again to update, reinstall or uninstall from a menu. It also cleans up old environment.d files left by the scripts above.

Tested on Bazzite 44 (GNOME deck image) with Millennium 3.6.2, themes included. Like the official installer, it needs the stable Steam client, because the 64-bit Steam beta doesn't work with Millennium yet (as noted above).

Repo: https://github.com/ethembeldagli/millennium-bazzite. Thanks to igor-tsiglyar, Shellke, LunRos and Zeglius, whose work in this thread made this possible.

[RingBandit]

After the latest Bazzite Update this isn't working anymore. Console Output looks like this:

:: Downloading Millennium 3.6.2...
:: Verifying checksum...
:: Installing to ~/.local/lib/millennium...
✓ Reinstalled Millennium 3.6.2.
  It loads in Desktop Mode and Game Mode.
  New Millennium releases install automatically (checked every 6 hours).
:: Starting Steam...
:: Waiting for Millennium to load (Steam may update itself first)...
! Steam started, but Millennium hasn't loaded yet. If it doesn't show up, log out and back in.
  From your next login it loads automatically. Run millennium-bazzite to change settings or remove it.

I did log out and back in (twice) and even rebooted, but it doesn't load anymore.
SteamRT3 is disabled in Steam Settings and I also tried reinstalling it with the same result.

[ethembeldagli]

srry i cant fix it i switched to cachyos

[SephirothWS]

After the latest Bazzite Update this isn't working anymore. Console Output looks like this:

:: Downloading Millennium 3.6.2...
:: Verifying checksum...
:: Installing to ~/.local/lib/millennium...
✓ Reinstalled Millennium 3.6.2.
  It loads in Desktop Mode and Game Mode.
  New Millennium releases install automatically (checked every 6 hours).
:: Starting Steam...
:: Waiting for Millennium to load (Steam may update itself first)...
! Steam started, but Millennium hasn't loaded yet. If it doesn't show up, log out and back in.
  From your next login it loads automatically. Run millennium-bazzite to change settings or remove it.

I did log out and back in (twice) and even rebooted, but it doesn't load anymore. SteamRT3 is disabled in Steam Settings and I also tried reinstalling it with the same result.

On Linux, Steam 64 bit just went stable, so even with SteamRT3 disabled, you're on 64-bits, gotta wait for millenium to patch for 64bit support.

[SephirothWS]

Now that Millennium released 3.6.3 which should support the 64bit client on Linux that Valve pushed to stable, believe there needs to be some adjustments to this script for it to detect the 64bit client and get it to get Millennium to load. None of the scripts on this page work now with the switch to 64bit on Linux for Bazzite.

[JankyMouse]

@SephirothWS Just made one. #983