diff --git a/.github/workflows/autobuild.yml b/.github/workflows/autobuild.yml
index 197faea7e1..4785ad73c7 100644
--- a/.github/workflows/autobuild.yml
+++ b/.github/workflows/autobuild.yml
@@ -95,7 +95,7 @@ jobs:
            - config_name:           AndroidAPK (artifact+codeQL)
              target_os:             android
              building_on_os:        ubuntu-20.04
-             cmd1_prebuild:         "sh ./autobuild/android/autobuild_apk_1_prepare.sh" # this step needs sh instead of bash for permissions
+             cmd1_prebuild:         "./autobuild/android/autobuild_apk_1_prepare.sh"
              cmd2_build:            "./autobuild/android/autobuild_apk_2_build.sh"
              cmd3_postbuild:        "./autobuild/android/autobuild_apk_3_copy_files.sh"
              uses_codeql:           true
@@ -103,7 +103,7 @@ jobs:
            - config_name:           Linux (artifacts+codeQL)
              target_os:             linux
              building_on_os:        ubuntu-18.04
-             cmd1_prebuild:         "sh ./autobuild/linux/autobuild_deb_1_prepare.sh" # this step needs sh instead of bash for permissions
+             cmd1_prebuild:         "./autobuild/linux/autobuild_deb_1_prepare.sh"
              cmd2_build:            "./autobuild/linux/autobuild_deb_2_build.sh"
              cmd3_postbuild:        "./autobuild/linux/autobuild_deb_3_copy_files.sh"
              uses_codeql:           true
diff --git a/ChangeLog b/ChangeLog
index db8ab4a9b0..9945da35d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -112,6 +112,9 @@
 - Internal: Prepared autobuild logic for upcoming Qt6 compatibility (#2328).
   (contributed by @hoffie, @softins)
 
+- Internal: Release build process has been refactored and uses pinned dependencies for better reproducibility now. (#2345)
+  (contributed by @hoffie)
+
 
 ### 3.8.1 (2021-10-23) ###
 
diff --git a/autobuild/android/archive___android_build_docker/Dockerfile b/autobuild/android/archive___android_build_docker/Dockerfile
deleted file mode 100644
index 478ac5222d..0000000000
--- a/autobuild/android/archive___android_build_docker/Dockerfile
+++ /dev/null
@@ -1,82 +0,0 @@
-FROM ubuntu:18.04
-
-#based on https://gitlab.com/vikingsoftware/qt5.12.4androiddocker
-#LABEL "Maintainer"="Guenter Schwann"
-#LABEL "version"="0.3"
-
-ENV DEBIAN_FRONTEND=noninteractive
-
-RUN apt-get update && \
-    apt-get install -y build-essential git zip unzip bzip2 p7zip-full wget curl chrpath libxkbcommon-x11-0 && \
-# Dependencies to create Android pkg
-    apt-get install -y openjdk-8-jre openjdk-8-jdk openjdk-8-jdk-headless gradle && \
-# Clean apt cache
-    apt-get clean && rm -rf /var/lib/apt/lists/*
-
-# Add Android tools and platform tools to PATH
-ENV ANDROID_HOME /opt/android/android-sdk
-ENV ANDROID_SDK_ROOT /opt/android/android-sdk
-ENV ANDROID_NDK_ROOT /opt/android/android-ndk
-
-# paths for Android SDK
-RUN mkdir -p ${ANDROID_SDK_ROOT}/cmdline-tools/latest/
-RUN mkdir -p ${ANDROID_SDK_ROOT}/build-tools/latest/
-
-# Install Android sdk
-#https://dl.google.com/android/repository/commandlinetools-linux-6858069_latest.zip
-#https://dl.google.com/android/repository/sdk-tools-linux-3859397.zip 
-RUN downloadfile="downloadfile"  && \
-	wget -q -O downloadfile https://dl.google.com/android/repository/commandlinetools-linux-6858069_latest.zip && \
-    unzip -q downloadfile && \
-    rm downloadfile && \
-    mv cmdline-tools/* /opt/android/android-sdk/cmdline-tools/latest/ && \
-    rm -r cmdline-tools
-
-# Install Android ndk
-#https://dl.google.com/android/repository/android-ndk-r19c-linux-x86_64.zip
-#https://dl.google.com/android/repository/android-ndk-r21d-linux-x86_64.zip
-RUN downloadfile="downloadfile"  && \
-	wget -q -O downloadfile https://dl.google.com/android/repository/android-ndk-r21d-linux-x86_64.zip && \
-    unzip -q downloadfile && \
-    rm downloadfile && \
-    mv android-ndk-r21d /opt/android/android-ndk
-
-# Add Android tools and platform tools to PATH
-ENV ANDROID_HOME /opt/android/android-sdk
-ENV ANDROID_SDK_ROOT /opt/android/android-sdk
-ENV ANDROID_NDK_ROOT /opt/android/android-ndk
-ENV PATH $PATH:$ANDROID_HOME/tools
-ENV PATH $PATH:$ANDROID_HOME/platform-tools
-ENV JAVA_HOME /usr/lib/jvm/java-8-openjdk-amd64/
-
-ENV ANDROID_NDK_HOST linux-x86_64
-
-ENV ANDROID_SDKMANAGER $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager
-
-# Install Android SDK
-RUN yes | $ANDROID_SDKMANAGER --licenses && $ANDROID_SDKMANAGER --update
-RUN $ANDROID_SDKMANAGER "platforms;android-17"
-RUN $ANDROID_SDKMANAGER "platforms;android-28"
-RUN $ANDROID_SDKMANAGER "platforms;android-30"
-RUN $ANDROID_SDKMANAGER "build-tools;28.0.3"
-RUN $ANDROID_SDKMANAGER "build-tools;30.0.2"
-
-
-#5.15.2
-ENV MY_QT_VERSION 5.15.2
-
-# Download / install Qt
-####ADD https://code.qt.io/cgit/qbs/qbs.git/plain/scripts/install-qt.sh ./
-COPY install-qt.sh /install-qt.sh
-RUN bash install-qt.sh --version $MY_QT_VERSION --target android --toolchain android qtbase qt3d qtdeclarative qtandroidextras qtconnectivity qtgamepad qtlocation qtmultimedia qtquickcontrols2 qtremoteobjects qtscxml qtsensors qtserialport qtsvg qtimageformats qttools qtspeech qtwebchannel qtwebsockets qtwebview qtxmlpatterns qttranslations 
-
-# Set the QTDIR environment variable
-ENV QTDIR="/opt/Qt/$MY_QT_VERSION/android"
-
-
-COPY build_qt_project.sh /build_qt_project.sh
-RUN chmod +x /build_qt_project.sh
-
-ENTRYPOINT /bin/bash /build_qt_project.sh
-
-
diff --git a/autobuild/android/archive___android_build_docker/__example__jamulusbuild.sh b/autobuild/android/archive___android_build_docker/__example__jamulusbuild.sh
deleted file mode 100755
index 82152e5d2e..0000000000
--- a/autobuild/android/archive___android_build_docker/__example__jamulusbuild.sh
+++ /dev/null
@@ -1,16 +0,0 @@
-#!/bin/bash
-
-# execute this file in an empty folder
-
-#clean & download code & change into folder
-rm -r jamulus
-git clone --recurse-submodules https://github.com/corrados/jamulus.git
-cd jamulus
-
-####################################################
-### these two lines run in toplevel folder of repo##
-####################################################
-
-#build & run docker
-docker build -t myjambuild ./android/automated_build
-docker run --rm -v `pwd`:/jamulus -w /jamulus -e CONFIG=release myjambuild
diff --git a/autobuild/android/archive___android_build_docker/action.yml b/autobuild/android/archive___android_build_docker/action.yml
deleted file mode 100644
index 64cb1789f1..0000000000
--- a/autobuild/android/archive___android_build_docker/action.yml
+++ /dev/null
@@ -1,7 +0,0 @@
-name: 'Run Android-Build-Docker'
-description: 'Run Android-Build-Docker'
-runs:
-  using: 'docker'
-  image: ./Dockerfile
-  args:
-    - CONFIG=release
diff --git a/autobuild/android/archive___android_build_docker/build_qt_project.sh b/autobuild/android/archive___android_build_docker/build_qt_project.sh
deleted file mode 100755
index aab6b6d545..0000000000
--- a/autobuild/android/archive___android_build_docker/build_qt_project.sh
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/bin/bash
-
-"${QTDIR}"/bin/qmake -spec android-clang CONFIG+="${CONFIG}"
-/opt/android/android-ndk/prebuilt/linux-x86_64/bin/make
-"${ANDROID_NDK_ROOT}"/prebuilt/"${ANDROID_NDK_HOST}"/bin/make INSTALL_ROOT=android-build -f Makefile install
-"${QTDIR}"/bin/androiddeployqt --input $(ls *.json) --output android-build --android-platform android-30 --jdk "${JAVA_HOME}" --gradle
diff --git a/autobuild/android/archive___android_build_docker/install-qt.sh b/autobuild/android/archive___android_build_docker/install-qt.sh
deleted file mode 100755
index 2bae78a963..0000000000
--- a/autobuild/android/archive___android_build_docker/install-qt.sh
+++ /dev/null
@@ -1,355 +0,0 @@
-#!/usr/bin/env bash
-#############################################################################
-##
-## Copyright (C) 2019 Richard Weickelt.
-## Contact: https://www.qt.io/licensing/
-##
-## This file is part of Qbs.
-##
-## $QT_BEGIN_LICENSE:LGPL$
-## Commercial License Usage
-## Licensees holding valid commercial Qt licenses may use this file in
-## accordance with the commercial license agreement provided with the
-## Software or, alternatively, in accordance with the terms contained in
-## a written agreement between you and The Qt Company. For licensing terms
-## and conditions see https://www.qt.io/terms-conditions. For further
-## information use the contact form at https://www.qt.io/contact-us.
-##
-## GNU Lesser General Public License Usage
-## Alternatively, this file may be used under the terms of the GNU Lesser
-## General Public License version 3 as published by the Free Software
-## Foundation and appearing in the file LICENSE.LGPL3 included in the
-## packaging of this file. Please review the following information to
-## ensure the GNU Lesser General Public License version 3 requirements
-## will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-##
-## GNU General Public License Usage
-## Alternatively, this file may be used under the terms of the GNU
-## General Public License version 2.0 or (at your option) the GNU General
-## Public license version 3 or any later version approved by the KDE Free
-## Qt Foundation. The licenses are as published by the Free Software
-## Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-## included in the packaging of this file. Please review the following
-## information to ensure the GNU General Public License requirements will
-## be met: https://www.gnu.org/licenses/gpl-2.0.html and
-## https://www.gnu.org/licenses/gpl-3.0.html.
-##
-## $QT_END_LICENSE$
-##
-#############################################################################
-
-## https://code.qt.io/cgit/qbs/qbs.git/tree/scripts/install-qt.sh
-
-set -eu
-
-function help() {
-    cat <<EOF
-usage: install-qt [options] [components]
-
-Examples
-  ./install-qt.sh --version 5.13.1 qtbase
-  ./install-qt.sh --version 5.14.0 --target android --toolchain any qtbase qtscript
-
-Positional arguments
-  components
-        SDK components to be installed. All possible components
-        can be found in the online repository at https://download.qt.io,
-        for instance: qtbase, qtdeclarative, qtscript, qttools, icu, ...
-
-        In addition to Qt packages, qtcreator is also accepted.
-
-        The actual availability of packages may differ depending on
-        target and toolchain.
-
-Options
-  -d, --directory <directory>
-        Root directory where to install the components.
-        Maps to C:/Qt on Windows, /opt/Qt on Linux, /usr/local/Qt on Mac
-        by default.
-
-  -f, --force
-        Force download and do not attempt to re-use an existing installation.
-
-  --host <host-os>
-        The host operating system. Can be one of linux_x64, mac_x64,
-        windows_x86. Auto-detected by default.
-
-  --target <target-platform>
-        The desired target platform. Can be one of desktop, android, ios.
-        The default value is desktop.
-
-  --toolchain <toolchain-type>
-        The toolchain that has been used to build the binaries.
-        Possible values depend on --host and --target, respectively:
-
-            linux_x64
-                android
-                    any, android_armv7, android_arm64_v8a
-                desktop
-                    gcc_64 (default)
-
-            mac_x64
-                android
-                    any, android_armv7, android_arm64_v8a
-                desktop
-                    clang_64 (default),
-                ios
-                    ios
-
-            windows_x86
-                android
-                    any, android_armv7, android_arm64_v8a
-                desktop
-                    win64_mingw73, win64_msvc2017_64 (default)
-
-  --version <version>
-        The desired Qt version. Currently supported are all versions
-        above 5.9.0.
-
-EOF
-}
-
-TARGET_PLATFORM=desktop
-COMPONENTS=
-VERSION=
-FORCE_DOWNLOAD=false
-MD5_TOOL=md5sum
-
-case "$OSTYPE" in
-    *linux*)
-        HOST_OS=linux_x64
-        INSTALL_DIR=/opt/Qt
-        TOOLCHAIN=gcc_64
-        ;;
-    *darwin*)
-        HOST_OS=mac_x64
-        INSTALL_DIR=/usr/local/Qt
-        TOOLCHAIN=clang_64
-        MD5_TOOL="md5 -r"
-        ;;
-    msys)
-        HOST_OS=windows_x86
-        INSTALL_DIR=/c/Qt
-        TOOLCHAIN=win64_msvc2015_64
-        ;;
-    *)
-        HOST_OS=
-        INSTALL_DIR=
-        ;;
-esac
-
-while [ $# -gt 0 ]; do
-    case "$1" in
-        --directory|-d)
-            INSTALL_DIR="$2"
-            shift
-            ;;
-        --force|-f)
-            FORCE_DOWNLOAD=true
-            ;;
-        --host)
-            HOST_OS="$2"
-            shift
-            ;;
-        --target)
-            TARGET_PLATFORM="$2"
-            shift
-            ;;
-        --toolchain)
-            TOOLCHAIN=$(echo $2 | tr '[A-Z]' '[a-z]')
-            shift
-            ;;
-        --version)
-            VERSION="$2"
-            shift
-            ;;
-        --help|-h)
-            help
-            exit 0
-            ;;
-        *)
-            COMPONENTS="${COMPONENTS} $1"
-            ;;
-    esac
-    shift
-done
-
-if [ -z "${HOST_OS}" ]; then
-    echo "No --host specified or auto-detection failed." >&2
-    exit 1
-fi
-
-if [ -z "${INSTALL_DIR}" ]; then
-    echo "No --directory specified or auto-detection failed." >&2
-    exit 1
-fi
-
-if [ -z "${VERSION}" ]; then
-    echo "No --version specified." >&2
-    exit 1
-fi
-
-if [ -z "${COMPONENTS}" ]; then
-    echo "No components specified." >&2
-    exit 1
-fi
-
-case "$TARGET_PLATFORM" in
-    android)
-        ;;
-    ios)
-        ;;
-    desktop)
-        ;;
-    *)
-        echo "Error: TARGET_PLATFORM=${TARGET_PLATFORM} is not valid." >&2
-        exit 1
-        ;;
-esac
-
-HASH=$(echo "${OSTYPE} ${TARGET_PLATFORM} ${TOOLCHAIN} ${VERSION} ${INSTALL_DIR}" | ${MD5_TOOL} | head -c 16)
-HASH_FILEPATH="${INSTALL_DIR}/${HASH}.manifest"
-INSTALLATION_IS_VALID=false
-if ! ${FORCE_DOWNLOAD} && [ -f "${HASH_FILEPATH}" ]; then
-    INSTALLATION_IS_VALID=true
-    while read filepath; do
-        if [ ! -e "${filepath}" ]; then
-            INSTALLATION_IS_VALID=false
-            break
-        fi
-    done <"${HASH_FILEPATH}"
-fi
-
-if ${INSTALLATION_IS_VALID}; then
-    echo "Already installed. Skipping download." >&2
-    exit 0
-fi
-
-MIRRORS="\
-    http://download.qt.io \
-    http://ftp.acc.umu.se/mirror/qt.io/qtproject \
-    http://qt.mirrors.tds.net/qt \
-    http://ftp.fau.de/qtproject \
-"
-
-for MIRROR in ${MIRRORS}; do
-    if curl "${MIRROR}/online" -s -f -o /dev/null; then
-        break;
-    else
-        echo "Server ${MIRROR} not availabe. Trying next alternative..." >&2
-        MIRROR=""
-    fi
-done
-
-DOWNLOAD_DIR=`mktemp -d 2>/dev/null || mktemp -d -t 'install-qt'`
-
-#
-# The repository structure is a mess. Try different URL variants
-#
-function compute_url(){
-    local COMPONENT=$1
-    local CURL="curl -s -L"
-    local BASE_URL="${MIRROR}/online/qtsdkrepository/${HOST_OS}/${TARGET_PLATFORM}"
-    local ANDROID_ARCH=$(echo ${TOOLCHAIN##android_})
-
-    if [[ "${COMPONENT}" =~ "qtcreator" ]]; then
-
-        SHORT_VERSION=${VERSION%??}
-        BASE_URL="${MIRROR}/official_releases/qtcreator"
-        REMOTE_PATH="${SHORT_VERSION}/${VERSION}/installer_source/${HOST_OS}/qtcreator.7z"
-        echo "${BASE_URL}/${REMOTE_PATH}"
-        return 0
-
-    else
-        REMOTE_BASES=(
-            # New repository format (>=6.0.0)
-            "qt6_${VERSION//./}/qt.qt6.${VERSION//./}.${TOOLCHAIN}"
-            "qt6_${VERSION//./}_${ANDROID_ARCH}/qt.qt6.${VERSION//./}.${TOOLCHAIN}"
-            "qt6_${VERSION//./}_${ANDROID_ARCH}/qt.qt6.${VERSION//./}.${COMPONENT}.${TOOLCHAIN}"
-            # New repository format (>=5.9.6)
-            "qt5_${VERSION//./}/qt.qt5.${VERSION//./}.${TOOLCHAIN}"
-            "qt5_${VERSION//./}/qt.qt5.${VERSION//./}.${COMPONENT}.${TOOLCHAIN}"
-            # Multi-abi Android since 5.14
-            "qt5_${VERSION//./}/qt.qt5.${VERSION//./}.${TARGET_PLATFORM}"
-            "qt5_${VERSION//./}/qt.qt5.${VERSION//./}.${COMPONENT}.${TARGET_PLATFORM}"
-            # Older repository format (<5.9.0)
-            "qt5_${VERSION//./}/qt.${VERSION//./}.${TOOLCHAIN}"
-            "qt5_${VERSION//./}/qt.${VERSION//./}.${COMPONENT}.${TOOLCHAIN}"
-        )
-
-        for REMOTE_BASE in ${REMOTE_BASES[*]}; do
-            REMOTE_PATH="$(${CURL} ${BASE_URL}/${REMOTE_BASE}/ | grep -o -E "[[:alnum:]_.\-]*7z" | grep "${COMPONENT}" | tail -1)"
-            if [ ! -z "${REMOTE_PATH}" ]; then
-                echo "${BASE_URL}/${REMOTE_BASE}/${REMOTE_PATH}"
-                return 0
-            fi
-        done
-    fi
-
-    echo "Could not determine a remote URL for ${COMPONENT} with version ${VERSION}">&2
-    exit 1
-}
-
-mkdir -p ${INSTALL_DIR}
-rm -f "${HASH_FILEPATH}"
-
-for COMPONENT in ${COMPONENTS}; do
-
-    URL="$(compute_url ${COMPONENT})"
-    echo "Downloading ${COMPONENT} ${URL}..." >&2
-    curl --progress-bar -L -o ${DOWNLOAD_DIR}/package.7z ${URL} >&2
-    7z x -y -o${INSTALL_DIR} ${DOWNLOAD_DIR}/package.7z >/dev/null 2>&1
-    7z l -ba -slt -y ${DOWNLOAD_DIR}/package.7z | tr '\\' '/' | sed -n -e "s|^Path\ =\ |${INSTALL_DIR}/|p" >> "${HASH_FILEPATH}" 2>/dev/null
-    rm -f ${DOWNLOAD_DIR}/package.7z
-
-    #
-    # conf file is needed for qmake
-    #
-    if [ "${COMPONENT}" == "qtbase" ]; then
-        if [[ "${TOOLCHAIN}" =~ "win64_mingw" ]]; then
-            SUBDIR="${TOOLCHAIN/win64_/}_64"
-        elif [[ "${TOOLCHAIN}" =~ "win32_mingw" ]]; then
-            SUBDIR="${TOOLCHAIN/win32_/}_32"
-        elif [[ "${TOOLCHAIN}" =~ "win64_msvc" ]]; then
-            SUBDIR="${TOOLCHAIN/win64_/}"
-        elif [[ "${TOOLCHAIN}" =~ "win32_msvc" ]]; then
-            SUBDIR="${TOOLCHAIN/win32_/}"
-        elif [[ "${TOOLCHAIN}" =~ "any" ]] && [[ "${TARGET_PLATFORM}" == "android" ]]; then
-            SUBDIR="android"
-        else
-            SUBDIR="${TOOLCHAIN}"
-        fi
-
-        if [ "${TARGET_PLATFORM}" == "android" ] && [ ! "${VERSION}" \< "6.0.0" ]; then
-            CONF_FILE="${INSTALL_DIR}/${VERSION}/${SUBDIR}/bin/target_qt.conf"
-            sed -i "s|target|../$TOOLCHAIN|g" "${CONF_FILE}"
-            sed -i "/HostPrefix/ s|$|gcc_64|g" "${CONF_FILE}"
-            ANDROID_QMAKE_FILE="${INSTALL_DIR}/${VERSION}/${SUBDIR}/bin/qmake"
-            QMAKE_FILE="${INSTALL_DIR}/${VERSION}/gcc_64/bin/qmake"
-            sed -i "s|\/home\/qt\/work\/install\/bin\/qmake|$QMAKE_FILE|g" "${ANDROID_QMAKE_FILE}"
-        else
-            CONF_FILE="${INSTALL_DIR}/${VERSION}/${SUBDIR}/bin/qt.conf"
-            echo "[Paths]" > ${CONF_FILE}
-            echo "Prefix = .." >> ${CONF_FILE}
-        fi
-
-        # Adjust the license to be able to run qmake
-        # sed with -i requires intermediate file on Mac OS
-        PRI_FILE="${INSTALL_DIR}/${VERSION}/${SUBDIR}/mkspecs/qconfig.pri"
-        sed -i.bak 's/Enterprise/OpenSource/g' "${PRI_FILE}"
-        sed -i.bak 's/licheck.*//g' "${PRI_FILE}"
-        rm "${PRI_FILE}.bak"
-
-        # Print the directory so that the caller can
-        # adjust the PATH variable.
-        echo $(dirname "${CONF_FILE}")
-    elif [[ "${COMPONENT}" =~ "qtcreator" ]]; then
-        if [ "${HOST_OS}" == "mac_x64" ]; then
-            echo "${INSTALL_DIR}/Qt Creator.app/Contents/MacOS"
-        else
-            echo "${INSTALL_DIR}/bin"
-        fi
-    fi
-
-done
-
diff --git a/autobuild/android/autobuild_apk_1_prepare.sh b/autobuild/android/autobuild_apk_1_prepare.sh
index e2970c7ce6..2e709e674c 100755
--- a/autobuild/android/autobuild_apk_1_prepare.sh
+++ b/autobuild/android/autobuild_apk_1_prepare.sh
@@ -1,4 +1,4 @@
-#!/bin/sh -e
+#!/bin/bash -e
 
 # autobuild_1_prepare: set up environment, install Qt & dependencies
 
@@ -7,26 +7,22 @@
 ###  PROCEDURE  ###
 ###################
 
-#FROM ubuntu:18.04
-#based on https://gitlab.com/vikingsoftware/qt5.12.4androiddocker
-#LABEL "Maintainer"="Guenter Schwann"
-#LABEL "version"="0.3"
+COMMANDLINETOOLS_VERSION=6858069
+ANDROID_NDK_VERSION=r21d
 
 export DEBIAN_FRONTEND="noninteractive"
 echo "::set-env name=DEBIAN_FRONTEND::${DEBIAN_FRONTEND}"
 
-sudo apt-get  update
-sudo apt-get -qq -y install  build-essential git zip unzip bzip2 p7zip-full wget curl chrpath libxkbcommon-x11-0
+sudo apt-get -qq update
 # Dependencies to create Android pkg
-sudo apt-get -qq -y install  openjdk-8-jre openjdk-8-jdk openjdk-8-jdk-headless gradle
-# Clean apt cache
-sudo apt-get clean
-rm -rf /var/lib/apt/lists/*
+sudo apt-get -qq -y install build-essential git zip unzip bzip2 p7zip-full wget curl chrpath libxkbcommon-x11-0 \
+    openjdk-8-jre openjdk-8-jdk openjdk-8-jdk-headless gradle
 
 # Add Android tools and platform tools to PATH
 export ANDROID_HOME="/opt/android/android-sdk"
-export ANDROID_SDK_ROOT="/opt/android/android-sdk"
+export ANDROID_SDK_ROOT="${ANDROID_HOME}"
 export ANDROID_NDK_ROOT="/opt/android/android-ndk"
+COMMANDLINETOOLS_DIR="${ANDROID_SDK_ROOT}"/cmdline-tools/latest/
 
 export PATH="${PATH}:${ANDROID_HOME}/tools"
 export PATH="${PATH}:${ANDROID_HOME}/platform-tools"
@@ -35,47 +31,30 @@ export JAVA_HOME="/usr/lib/jvm/java-8-openjdk-amd64/"
 # other variables
 export MY_QT_VERSION="5.15.2"
 export ANDROID_NDK_HOST="linux-x86_64"
-export ANDROID_SDKMANAGER="${ANDROID_HOME}/cmdline-tools/latest/bin/sdkmanager"
+export ANDROID_SDKMANAGER="${COMMANDLINETOOLS_DIR}/bin/sdkmanager"
 
 # paths for Android SDK
-mkdir -p "${ANDROID_SDK_ROOT}"/cmdline-tools/latest/
+mkdir -p "${COMMANDLINETOOLS_DIR}"
 mkdir -p "${ANDROID_SDK_ROOT}"/build-tools/latest/
 
 # Install Android sdk
-#https://dl.google.com/android/repository/commandlinetools-linux-6858069_latest.zip
-#https://dl.google.com/android/repository/sdk-tools-linux-3859397.zip
-downloadfile="downloadfile"
-wget -q -O downloadfile https://dl.google.com/android/repository/commandlinetools-linux-6858069_latest.zip
+wget -q -O downloadfile https://dl.google.com/android/repository/commandlinetools-linux-${COMMANDLINETOOLS_VERSION}_latest.zip
 unzip -q downloadfile
-rm downloadfile
-mv cmdline-tools/* /opt/android/android-sdk/cmdline-tools/latest/
-rm -r cmdline-tools
+mv cmdline-tools/* "${COMMANDLINETOOLS_DIR}"
 
 # Install Android ndk
-#https://dl.google.com/android/repository/android-ndk-r19c-linux-x86_64.zip
-#https://dl.google.com/android/repository/android-ndk-r21d-linux-x86_64.zip
-downloadfile="downloadfile"
-wget -q -O downloadfile https://dl.google.com/android/repository/android-ndk-r21d-linux-x86_64.zip
+wget -q -O downloadfile https://dl.google.com/android/repository/android-ndk-${ANDROID_NDK_VERSION}-linux-x86_64.zip
 unzip -q downloadfile
-rm downloadfile
-mv android-ndk-r21d /opt/android/android-ndk
-
+mv android-ndk-${ANDROID_NDK_VERSION} "${ANDROID_NDK_ROOT}"
 
 # Install Android SDK
 yes | "${ANDROID_SDKMANAGER}" --licenses
-#echo yes | $ANDROID_SDKMANAGER --licenses
 "${ANDROID_SDKMANAGER}" --update
-#$ANDROID_SDKMANAGER "platforms;android-17"
-#$ANDROID_SDKMANAGER "platforms;android-28"
 "${ANDROID_SDKMANAGER}" "platforms;android-30"
-#$ANDROID_SDKMANAGER "build-tools;28.0.3"
 "${ANDROID_SDKMANAGER}" "build-tools;30.0.2"
 
 
-
 # Download / install Qt
-####ADD https://code.qt.io/cgit/qbs/qbs.git/plain/scripts/install-qt.sh ./
-#COPY install-qt.sh /install-qt.sh
 THIS_SCRIPT=$(readlink -f "${0}")
 # Absolute path this script is in, thus /home/user/bin
 THIS_SCRIPT_PATH=$(dirname "${THIS_SCRIPT}")
@@ -84,14 +63,13 @@ bash "${THIS_SCRIPT_PATH}"/install-qt.sh --version "${MY_QT_VERSION}" --target a
 # Set the QTDIR environment variable
 export QTDIR="/opt/Qt/${MY_QT_VERSION}/android"
 
-
 #necessary
 echo "::set-env name=QTDIR::${QTDIR}"
 echo "::set-env name=ANDROID_NDK_ROOT::${ANDROID_NDK_ROOT}"
 echo "::set-env name=ANDROID_NDK_HOST::${ANDROID_NDK_HOST}"
 echo "::set-env name=JAVA_HOME::${JAVA_HOME}"
 
-#nce to have
+#nice to have
 echo "::set-env name=ANDROID_HOME::${ANDROID_HOME}"
 echo "::set-env name=ANDROID_SDK_ROOT::${ANDROID_SDK_ROOT}"
 echo "::set-env name=PATH::${PATH}"
diff --git a/autobuild/android/autobuild_apk_2_build.sh b/autobuild/android/autobuild_apk_2_build.sh
index 3a60b2e41b..e7d532edff 100755
--- a/autobuild/android/autobuild_apk_2_build.sh
+++ b/autobuild/android/autobuild_apk_2_build.sh
@@ -15,7 +15,6 @@ source $(dirname $(readlink -f "${BASH_SOURCE[0]}"))/../ensure_THIS_JAMULUS_PROJ
 
 cd "${THIS_JAMULUS_PROJECT_PATH}"
 
-#$QTDIR/bin/qmake -spec android-clang CONFIG+=$CONFIG
 "${QTDIR}"/bin/qmake -spec android-clang CONFIG+=release
 echo .
 echo .
diff --git a/autobuild/mac/artifacts/autobuild_mac_1_prepare.sh b/autobuild/mac/artifacts/autobuild_mac_1_prepare.sh
index c9206b5cb2..6b496575bd 100755
--- a/autobuild/mac/artifacts/autobuild_mac_1_prepare.sh
+++ b/autobuild/mac/artifacts/autobuild_mac_1_prepare.sh
@@ -1,4 +1,4 @@
-#!/bin/sh -e
+#!/bin/bash -e
 
 # autobuild_1_prepare: set up environment, install Qt & dependencies
 
@@ -7,19 +7,21 @@ if [ "$#" -ne "1" ]; then
     exit 1
 fi
 
+QT_DIR=/usr/local/opt/qt
 QT_VER=$1
+AQTINSTALL_VERSION=2.0.5
 
 ###################
 ###  PROCEDURE  ###
 ###################
 
 echo "Install dependencies..."
-python3 -m pip install aqtinstall
-python3 -m aqt install-qt --outputdir /usr/local/opt/qt mac desktop ${QT_VER}
+python3 -m pip install "aqtinstall==${AQTINSTALL_VERSION}"
+python3 -m aqt install-qt --outputdir "${QT_DIR}" mac desktop ${QT_VER}
 
-# add the qt binaries to the path
+# Add the qt binaries to the PATH.
 # The clang_64 entry can be dropped when Qt <6.2 compatibility is no longer needed.
-for qt_path in /usr/local/opt/qt/${QT_VER}/macos/bin /usr/local/opt/qt/${QT_VER}/clang_64/bin; do
+for qt_path in "${QT_DIR}"/${QT_VER}/macos/bin "${QT_DIR}"/${QT_VER}/clang_64/bin; do
     if [[ -d $qt_path ]]; then
 		export -p PATH="${qt_path}:${PATH}"
         break
@@ -27,4 +29,3 @@ for qt_path in /usr/local/opt/qt/${QT_VER}/macos/bin /usr/local/opt/qt/${QT_VER}
 done
 echo "::set-env name=PATH::${PATH}"
 echo "the path is ${PATH}"
-
diff --git a/autobuild/mac/codeQL/autobuild_mac_1_prepare.sh b/autobuild/mac/codeQL/autobuild_mac_1_prepare.sh
index 51d7f25c6e..6b496575bd 100755
--- a/autobuild/mac/codeQL/autobuild_mac_1_prepare.sh
+++ b/autobuild/mac/codeQL/autobuild_mac_1_prepare.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/bash -e
 
 # autobuild_1_prepare: set up environment, install Qt & dependencies
 
@@ -7,19 +7,21 @@ if [ "$#" -ne "1" ]; then
     exit 1
 fi
 
+QT_DIR=/usr/local/opt/qt
 QT_VER=$1
+AQTINSTALL_VERSION=2.0.5
 
 ###################
 ###  PROCEDURE  ###
 ###################
 
 echo "Install dependencies..."
-python3 -m pip install aqtinstall
-python3 -m aqt install-qt --outputdir /usr/local/opt/qt mac desktop ${QT_VER}
+python3 -m pip install "aqtinstall==${AQTINSTALL_VERSION}"
+python3 -m aqt install-qt --outputdir "${QT_DIR}" mac desktop ${QT_VER}
 
-# add the qt binaries to the path
+# Add the qt binaries to the PATH.
 # The clang_64 entry can be dropped when Qt <6.2 compatibility is no longer needed.
-for qt_path in /usr/local/opt/qt/${QT_VER}/macos/bin /usr/local/opt/qt/${QT_VER}/clang_64/bin; do
+for qt_path in "${QT_DIR}"/${QT_VER}/macos/bin "${QT_DIR}"/${QT_VER}/clang_64/bin; do
     if [[ -d $qt_path ]]; then
 		export -p PATH="${qt_path}:${PATH}"
         break
@@ -27,4 +29,3 @@ for qt_path in /usr/local/opt/qt/${QT_VER}/macos/bin /usr/local/opt/qt/${QT_VER}
 done
 echo "::set-env name=PATH::${PATH}"
 echo "the path is ${PATH}"
-
diff --git a/autobuild/windows/autobuild_windowsinstaller_1_prepare.ps1 b/autobuild/windows/autobuild_windowsinstaller_1_prepare.ps1
index 094720e413..19d4ca1fc3 100644
--- a/autobuild/windows/autobuild_windowsinstaller_1_prepare.ps1
+++ b/autobuild/windows/autobuild_windowsinstaller_1_prepare.ps1
@@ -19,9 +19,16 @@ $ErrorActionPreference = "Stop"
 ###  PROCEDURE  ###
 ###################
 
+$QtDir = 'C:\Qt'
+$Qt32Version = "5.15.2"
+$Qt64Version = "5.15.2"
+$AqtinstallVersion = "2.0.5"
+$JackVersion = "1.9.17"
+$MsvcVersion = "2019"
+
 echo "Install Qt..."
 # Install Qt
-pip install aqtinstall
+pip install "aqtinstall==$AqtinstallVersion"
 if ( !$? )
 {
 		throw "pip install aqtinstall failed with exit code $LastExitCode"
@@ -29,7 +36,7 @@ if ( !$? )
 
 echo "Get Qt 64 bit..."
 # intermediate solution if the main server is down: append e.g. " -b https://mirrors.ocf.berkeley.edu/qt/" to the "aqt"-line below
-aqt install-qt --outputdir C:\Qt windows desktop 5.15.2 win64_msvc2019_64
+aqt install-qt --outputdir "${QtDir}" windows desktop "${Qt64Version}" "win64_msvc${MsvcVersion}_64"
 if ( !$? )
 {
 		throw "64bit Qt installation failed with exit code $LastExitCode"
@@ -37,7 +44,7 @@ if ( !$? )
 
 echo "Get Qt 32 bit..."
 # intermediate solution if the main server is down: append e.g. " -b https://mirrors.ocf.berkeley.edu/qt/" to the "aqt"-line below
-aqt install-qt --outputdir C:\Qt windows desktop 5.15.2 win32_msvc2019
+aqt install-qt --outputdir "${QtDir}" windows desktop "${Qt32Version}" "win32_msvc${MsvcVersion}"
 if ( !$? )
 {
 		throw "32bit Qt installation failed with exit code $LastExitCode"
@@ -52,7 +59,7 @@ if ($BuildOption -Eq "jackonwindows")
 {
     echo "Install JACK2 64-bit..."
     # Install JACK2 64-bit
-    choco install --no-progress -y jack
+    choco install --no-progress -y jack --version "${JackVersion}"
     if ( !$? )
     {
         throw "64bit jack installation failed with exit code $LastExitCode"
@@ -60,7 +67,7 @@ if ($BuildOption -Eq "jackonwindows")
 
     echo "Install JACK2 32-bit..."
     # Install JACK2 32-bit (need to force choco install as it detects 64 bits as installed)
-    choco install --no-progress -y -f --forcex86 jack
+    choco install --no-progress -y -f --forcex86 jack --version "${JackVersion}"
     if ( !$? )
     {
         throw "32bit jack installation failed with exit code $LastExitCode"