diff --git a/config/functions b/config/functions
index 050498b604..c232a8a97d 100644
--- a/config/functions
+++ b/config/functions
@@ -1261,11 +1261,15 @@ pkg_lock_status() {
   local status="$1" pkg="$2" task="$3" msg="$4"
   local this_job="${MTJOBID}" line
 
-  printf -v line "%s: <%05d> [%02d/%0*d] %-7s %-7s %-35s" \
-    "$(date +%Y-%m-%d\ %H:%M:%S.%N)" $$ ${this_job} ${#MTMAXJOBS} ${PARALLEL_SEQ:-0} "${status}" "${task}" "${pkg}"
-  [ -n "${msg}" ] && line+=" (${msg})"
+  (
+    flock --exclusive 94
 
-  echo "${line}" >>"${THREAD_CONTROL}/history"
+    printf -v line "%s: <%05d> [%02d/%0*d] %-7s %-7s %-35s" \
+    "$(date +%Y-%m-%d\ %H:%M:%S.%N)" $$ ${this_job} ${#MTMAXJOBS} ${PARALLEL_SEQ:-0} "${status}" "${task}" "${pkg}"
+    [ -n "${msg}" ] && line+=" (${msg})"
+
+    echo "${line}" >>"${THREAD_CONTROL}/history"
+  ) 94>"${THREAD_CONTROL}/locks/.history"
 
   [ "${DASHBOARD}" != "no" ] && update_dashboard "${status}" "${pkg}" "${task}" "${msg}"
 
diff --git a/config/multithread b/config/multithread
index 1c14ddfc70..26a9c2ceb6 100644
--- a/config/multithread
+++ b/config/multithread
@@ -144,7 +144,7 @@ start_multithread_build() {
   local singlethread buildopts
 
   # init thread control folder
-  rm -fr "${THREAD_CONTROL}"
+  rm -rf "${THREAD_CONTROL}"
   mkdir -p "${THREAD_CONTROL}/locks"
   echo -1 >"${THREAD_CONTROL}/progress.prev"
   echo 0 >"${THREAD_CONTROL}/progress"
diff --git a/packages/addons/addon-depends/libimobiledevice/package.mk b/packages/addons/addon-depends/libimobiledevice/package.mk
index 08e409426e..62e040e684 100644
--- a/packages/addons/addon-depends/libimobiledevice/package.mk
+++ b/packages/addons/addon-depends/libimobiledevice/package.mk
@@ -17,5 +17,6 @@ PKG_CONFIGURE_OPTS_TARGET="--enable-static \
                            --disable-largefile"
 
 post_makeinstall_target() {
-  cp $PKG_BUILD/common/utils.h $SYSROOT_PREFIX/usr/include/libimobiledevice/
+  mkdir -p "${SYSROOT_PREFIX}/usr/include/lib/libimobiledevice"
+    cp ${PKG_BUILD}/common/utils.h "${SYSROOT_PREFIX}/usr/include/libimobiledevice"
 }
diff --git a/packages/addons/addon-depends/qtbase/package.mk b/packages/addons/addon-depends/qtbase/package.mk
index c8a6583281..a6ee847c25 100644
--- a/packages/addons/addon-depends/qtbase/package.mk
+++ b/packages/addons/addon-depends/qtbase/package.mk
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 # Copyright (C) 2009-2016 Lukas Rusak (lrusak@libreelec.tv)
+# Copyright (C) 2019-present Team LibreELEC (https://libreelec.tv)
 
 PKG_NAME="qtbase"
 PKG_VERSION="5.6.2"
@@ -11,8 +12,8 @@ PKG_DEPENDS_TARGET="pcre zlib"
 PKG_LONGDESC="A cross-platform application and UI framework."
 
 PKG_CONFIGURE_OPTS_TARGET="-prefix /usr
-                           -sysroot $SYSROOT_PREFIX
-                           -hostprefix $TOOLCHAIN
+                           -sysroot "${SYSROOT_PREFIX}"
+                           -hostprefix "${TOOLCHAIN}"
                            -device linux-libreelec-g++
                            -opensource -confirm-license
                            -release
@@ -52,31 +53,42 @@ PKG_CONFIGURE_OPTS_TARGET="-prefix /usr
 
 configure_target() {
   QMAKE_CONF_DIR="mkspecs/devices/linux-libreelec-g++"
-  QMAKE_CONF="${QMAKE_CONF_DIR}/qmake.conf"
 
   cd ..
-  mkdir -p $QMAKE_CONF_DIR
-  echo "MAKEFILE_GENERATOR       = UNIX" > $QMAKE_CONF
-  echo "CONFIG                  += incremental" >> $QMAKE_CONF
-  echo "QMAKE_INCREMENTAL_STYLE  = sublib" >> $QMAKE_CONF
-  echo "include(../../common/linux.conf)" >> $QMAKE_CONF
-  echo "include(../../common/gcc-base-unix.conf)" >> $QMAKE_CONF
-  echo "include(../../common/g++-unix.conf)" >> $QMAKE_CONF
-  echo "load(device_config)" >> $QMAKE_CONF
-  echo "QMAKE_CC                = $CC" >> $QMAKE_CONF
-  echo "QMAKE_CXX               = $CXX" >> $QMAKE_CONF
-  echo "QMAKE_LINK              = $CXX" >> $QMAKE_CONF
-  echo "QMAKE_LINK_SHLIB        = $CXX" >> $QMAKE_CONF
-  echo "QMAKE_AR                = $AR cqs" >> $QMAKE_CONF
-  echo "QMAKE_OBJCOPY           = $OBJCOPY" >> $QMAKE_CONF
-  echo "QMAKE_NM                = $NM -P" >> $QMAKE_CONF
-  echo "QMAKE_STRIP             = $STRIP" >> $QMAKE_CONF
-  echo "QMAKE_CFLAGS = $CFLAGS" >> $QMAKE_CONF
-  echo "QMAKE_CXXFLAGS = $CXXFLAGS" >> $QMAKE_CONF
-  echo "QMAKE_LFLAGS = $LDFLAGS" >> $QMAKE_CONF
-  echo "load(qt_config)" >> $QMAKE_CONF
-  echo '#include "../../linux-g++/qplatformdefs.h"' >> $QMAKE_CONF_DIR/qplatformdefs.h
+  mkdir -p ${QMAKE_CONF_DIR}
+
+  cat >"${QMAKE_CONF_DIR}/qmake.conf" <<EOF
+MAKEFILE_GENERATOR      = UNIX
+CONFIG                 += incremental
+QMAKE_INCREMENTAL_STYLE = sublib
+include(../../common/linux.conf)
+include(../../common/gcc-base-unix.conf)
+include(../../common/g++-unix.conf)
+load(device_config)
+QMAKE_CC         = ${CC}
+QMAKE_CXX        = ${CXX}
+QMAKE_LINK       = ${CXX}
+QMAKE_LINK_SHLIB = ${CXX}
+QMAKE_AR         = ${AR} cqs
+QMAKE_OBJCOPY    = ${OBJCOPY}
+QMAKE_NM         = ${NM} -P
+QMAKE_STRIP      = ${STRIP}
+QMAKE_CFLAGS     = ${CFLAGS}
+QMAKE_CXXFLAGS   = ${CXXFLAGS}
+QMAKE_LFLAGS     = ${LDFLAGS}
+load(qt_config)
+EOF
+
+  cat >"${QMAKE_CONF_DIR}/qplatformdefs.h" <<EOF
+#include "../../linux-g++/qplatformdefs.h"
+EOF
 
   unset CC CXX LD RANLIB AR AS CPPFLAGS CFLAGS LDFLAGS CXXFLAGS
-  ./configure $PKG_CONFIGURE_OPTS_TARGET
+  ./configure ${PKG_CONFIGURE_OPTS_TARGET}
+}
+
+post_makeinstall_target() {
+  # Qt installs directly to $SYSROOT_PREFIX so don't rely on scripts/build fixing this up
+  # PKG_ORIG_SYSROOT_PREFIX will be undefined when performing a legacy build
+  sed -e "s:\(['= ]\)/usr:\\1${PKG_ORIG_SYSROOT_PREFIX:-${SYSROOT_PREFIX}}/usr:g" -i "${PKG_ORIG_SYSROOT_PREFIX:-${SYSROOT_PREFIX}}/usr/lib"/libQt*.la
 }
diff --git a/packages/audio/libopenmpt/package.mk b/packages/audio/libopenmpt/package.mk
index cad60b79db..af38eb6167 100644
--- a/packages/audio/libopenmpt/package.mk
+++ b/packages/audio/libopenmpt/package.mk
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 # Copyright (C) 2009-2016 Stephan Raue (stephan@openelec.tv)
+# Copyright (C) 2019-present Team LibreELEC (https://libreelec.tv)
 
 PKG_NAME="libopenmpt"
 PKG_VERSION="0.3.1"
@@ -7,7 +8,7 @@ PKG_SHA256="6fc5614926edd523d5585e40fdaf0b2ea08689d4dc91de49511d02503744cbb5"
 PKG_LICENSE="BSD"
 PKG_SITE="http://lib.openmpt.org/libopenmpt/"
 PKG_URL="http://lib.openmpt.org/files/libopenmpt/src/${PKG_NAME}-${PKG_VERSION}+release.autotools.tar.gz"
-PKG_DEPENDS_TARGET="toolchain libogg libvorbis"
+PKG_DEPENDS_TARGET="toolchain libogg libvorbis zlib"
 PKG_LONGDESC="libopenmpt renders mod music files as raw audio data, for playing or conversion."
 PKG_BUILD_FLAGS="+pic"
 
diff --git a/packages/mediacenter/kodi-binary-addons/pvr.zattoo/package.mk b/packages/mediacenter/kodi-binary-addons/pvr.zattoo/package.mk
index cce58915b7..1d8db26cfa 100644
--- a/packages/mediacenter/kodi-binary-addons/pvr.zattoo/package.mk
+++ b/packages/mediacenter/kodi-binary-addons/pvr.zattoo/package.mk
@@ -9,7 +9,7 @@ PKG_ARCH="any"
 PKG_LICENSE="GPL"
 PKG_SITE="http://www.kodi.tv"
 PKG_URL="https://github.com/rbuehlma/pvr.zattoo/archive/$PKG_VERSION.tar.gz"
-PKG_DEPENDS_TARGET="toolchain kodi-platform"
+PKG_DEPENDS_TARGET="toolchain kodi-platform tinyxml2"
 PKG_SECTION=""
 PKG_SHORTDESC="pvr.zattoo"
 PKG_LONGDESC="pvr.zattoo"
diff --git a/packages/mediacenter/kodi-binary-addons/screensaver.asterwave/package.mk b/packages/mediacenter/kodi-binary-addons/screensaver.asterwave/package.mk
index 417feb5c77..068499d1e7 100644
--- a/packages/mediacenter/kodi-binary-addons/screensaver.asterwave/package.mk
+++ b/packages/mediacenter/kodi-binary-addons/screensaver.asterwave/package.mk
@@ -10,7 +10,7 @@ PKG_ARCH="any"
 PKG_LICENSE="GPL"
 PKG_SITE="https://github.com/notspiff/screensaver.asterwave"
 PKG_URL="https://github.com/notspiff/screensaver.asterwave/archive/$PKG_VERSION.tar.gz"
-PKG_DEPENDS_TARGET="toolchain kodi-platform soil"
+PKG_DEPENDS_TARGET="toolchain kodi-platform soil glm"
 PKG_SECTION=""
 PKG_SHORTDESC="screensaver.asterwave"
 PKG_LONGDESC="screensaver.asterwave"
diff --git a/packages/mediacenter/kodi-binary-addons/screensaver.cpblobs/package.mk b/packages/mediacenter/kodi-binary-addons/screensaver.cpblobs/package.mk
index ce47f5515a..7c247e439b 100644
--- a/packages/mediacenter/kodi-binary-addons/screensaver.cpblobs/package.mk
+++ b/packages/mediacenter/kodi-binary-addons/screensaver.cpblobs/package.mk
@@ -10,7 +10,7 @@ PKG_ARCH="any"
 PKG_LICENSE="GPL"
 PKG_SITE="https://github.com/notspiff/screensaver.cpblobs"
 PKG_URL="https://github.com/notspiff/screensaver.cpblobs/archive/$PKG_VERSION.tar.gz"
-PKG_DEPENDS_TARGET="toolchain kodi-platform soil"
+PKG_DEPENDS_TARGET="toolchain kodi-platform soil glm"
 PKG_SECTION=""
 PKG_SHORTDESC="screensaver.cpblobs"
 PKG_LONGDESC="screensaver.cpblobs"
diff --git a/scripts/build b/scripts/build
index c123a5b8b9..a4be68d83f 100755
--- a/scripts/build
+++ b/scripts/build
@@ -373,13 +373,17 @@ fi
 
 pkg_call_exists post_make_$TARGET && pkg_call post_make_$TARGET
 
-# make install writes directly to sysroot which then needs fixing up - this is racy
-if listcontains "configure:target cmake-make:target autotools:target make:target" "${PKG_TOOLCHAIN}:${TARGET}"; then
-  acquire_exclusive_lock "${PKG_NAME}:${TARGET}" "build"
-  PKG_NEED_UNLOCK=yes
-else
-  PKG_NEED_UNLOCK=no
-fi
+# Hack around directly writing/modifying the content of a shared sysroot
+# by temporarily installing new files to a package specific sysroot
+PKG_ORIG_SYSROOT_PREFIX="${SYSROOT_PREFIX}"
+export SYSROOT_PREFIX="${BUILD}/.sysroot/${PKG_NAME}.${TARGET}"
+rm -rf "${SYSROOT_PREFIX}"
+
+# Create common sysroot directories as some packages expect them to exist.
+# TODO: Fix those packages so we don't need to pre-create directories.
+for d in /usr/lib /usr/include /usr/bin /usr/lib/pkgconfig; do
+  mkdir -p "${SYSROOT_PREFIX}${d}"
+done
 
 # make install
 pkg_call_exists pre_makeinstall_$TARGET && pkg_call pre_makeinstall_$TARGET
@@ -422,14 +426,26 @@ fi
 
 pkg_call_exists post_makeinstall_$TARGET && pkg_call post_makeinstall_$TARGET
 
-# This is the racy part - one or more processes may be creating, modifying or deleting
-# $SYSROOT_PREFIX/usr/lib/*.la files while another (eg. this) process is rewriting the same
-# files as it fixes up the libdir prefix. Eugh.
-for i in $(find $SYSROOT_PREFIX/usr/lib/ -name "*.la" 2>/dev/null); do
-  sed -e "s:\(['= ]\)/usr:\\1$SYSROOT_PREFIX/usr:g" -i $i
+# Fixup temporary sysroot references to the shared sysroot
+for i in $(find "${SYSROOT_PREFIX}/usr/lib" -type f -name "*.la" 2>/dev/null); do
+  sed -e "s:\(['= ]\)/usr:\\1${PKG_ORIG_SYSROOT_PREFIX}/usr:g" -i "${i}"
+done
+for i in $(find "${SYSROOT_PREFIX}/usr/bin" -type f -name "*-config" 2>/dev/null); do
+  sed -e "s#${SYSROOT_PREFIX}/usr#${PKG_ORIG_SYSROOT_PREFIX}/usr#g" -i "${i}"
+done
+for i in $(find "${SYSROOT_PREFIX}/usr/lib" -type f -name "*.pc" 2>/dev/null); do
+  sed -e "s#${SYSROOT_PREFIX}/usr#${PKG_ORIG_SYSROOT_PREFIX}/usr#g" -i "${i}"
+done
+for i in $(find "${SYSROOT_PREFIX}/usr"/{lib,share} -type f -name "*.cmake" 2>/dev/null); do
+  sed -e "s#${SYSROOT_PREFIX}/usr#${PKG_ORIG_SYSROOT_PREFIX}/usr#g" -i "${i}"
 done
 
-[ "${PKG_NEED_UNLOCK}" = "yes" ] && release_exclusive_lock "${PKG_NAME}:${TARGET}" "build"
+# Transfer the new sysroot content to the shared sysroot
+mkdir -p "${PKG_ORIG_SYSROOT_PREFIX}"
+cp -PR "${SYSROOT_PREFIX}"/* "${PKG_ORIG_SYSROOT_PREFIX}"
+rm -rf "${SYSROOT_PREFIX}"
+
+export SYSROOT_PREFIX="${PKG_ORIG_SYSROOT_PREFIX}"
 
 if [ "$TARGET" = "target" -o "$TARGET" = "init" ]; then
   if [ -d $INSTALL ]; then
diff --git a/scripts/genbuildplan.py b/scripts/genbuildplan.py
index 73a5d175d5..3922f886a7 100755
--- a/scripts/genbuildplan.py
+++ b/scripts/genbuildplan.py
@@ -313,7 +313,7 @@ def processPackages(args, packages, build):
                     elif not args.ignore_invalid:
                         raise Exception("Invalid package! Package %s cannot be found for this PROJECT/DEVICE/ARCH" % dfq_p)
 
-    # To each target-specific node, add the correspnding
+    # To each target-specific node, add the corresponding
     # target-specific dependency nodes ("edges")
     for name in node_map:
         node = node_map[name]
diff --git a/scripts/image b/scripts/image
index 70830e2050..ba9b1aa9e3 100755
--- a/scripts/image
+++ b/scripts/image
@@ -13,6 +13,8 @@ unset _CACHE_PACKAGE_LOCAL _CACHE_PACKAGE_GLOBAL _DEBUG_DEPENDS_LIST _DEBUG_PACK
 show_config
 save_build_config
 
+${SCRIPTS}/checkdeps
+
 # Setup both toolchain cmake configs to avoid potentially racy behaviour later.
 # Use a fork for host to isolate any variable modifications.
 ( setup_toolchain host )
diff --git a/scripts/unpack b/scripts/unpack
index 1fc760aefc..5415acf5aa 100755
--- a/scripts/unpack
+++ b/scripts/unpack
@@ -54,7 +54,7 @@ if [ -d "$SOURCES/${PKG_NAME}" -o -d "$PKG_DIR/sources" ]; then
 
   # unpack into a unique location as unpacking into a single ${BUILD} directory is not thread-safe
   PKG_UNPACK_DIR="${BUILD}/.unpack/${PKG_NAME}"
-  rm -fr "${PKG_UNPACK_DIR}"
+  rm -rf "${PKG_UNPACK_DIR}"
   mkdir -p "${PKG_UNPACK_DIR}"
 
   pkg_call_exists pre_unpack && pkg_call pre_unpack
@@ -84,7 +84,7 @@ if [ -d "$SOURCES/${PKG_NAME}" -o -d "$PKG_DIR/sources" ]; then
   fi
 
   # cleanup
-  rm -fr "${PKG_UNPACK_DIR}"
+  rm -rf "${PKG_UNPACK_DIR}"
 
   if [ -d "$PKG_DIR/sources" ]; then
     [ ! -d "$PKG_BUILD" ] && mkdir -p "$PKG_BUILD"