diff --git a/aegis.sh b/aegis.sh
index 28531b1bec..91a175d56c 100644
--- a/aegis.sh
+++ b/aegis.sh
@@ -13,6 +13,9 @@ source: https://github.com/AliceO2Group/AEGIS.git
 prepend_path:
   LD_LIBRARY_PATH: "$AEGIS_ROOT/lib"
   ROOT_INCLUDE_PATH: "$AEGIS_ROOT/include"
+valid_defaults:
+  - o2
+  - jw
 ---
 #!/bin/bash -e
 FVERSION=`gfortran --version | grep -i fortran | sed -e 's/.* //' | cut -d. -f1`
diff --git a/apmon-cpp.sh b/apmon-cpp.sh
index 027162a583..9e988f5fa1 100644
--- a/apmon-cpp.sh
+++ b/apmon-cpp.sh
@@ -12,6 +12,12 @@ rsync -a --exclude='**/.git' --delete --delete-excluded \
       $SOURCEDIR/ ./
 autoreconf -ivf
 
+case $ARCHITECTURE in
+  arch*)
+    LIBTIRPC_ROOT=/usr
+  ;;
+esac
+
 if [[ -n ${LIBTIRPC_ROOT} ]];
 then
   export CXXFLAGS="${CXXFLAGS} -I${LIBTIRPC_ROOT}/include/tirpc"
diff --git a/arrow.sh b/arrow.sh
index 0e6bb354bb..5021f95d00 100644
--- a/arrow.sh
+++ b/arrow.sh
@@ -23,6 +23,7 @@ env:
 ---
 #!/bin/bash -e
 mkdir -p "$INSTALLROOT"
+SONAME=so
 case $ARCHITECTURE in
   osx*)
     # If we preferred system tools, we need to make sure we can pick them up.
@@ -43,9 +44,17 @@ __ZNK4llvm*
 EOF
     CMAKE_SHARED_LINKER_FLAGS="-Wl,-unexported_symbols_list,$PWD/no-llvm-symbols.txt"
   ;;
+  arch*)
+    #[[ ! $RE2_ROOT ]] && RE2_ROOT=/usr
+    [[ ! $LZ4_ROOT ]] && LZ4_ROOT=$(dirname $(dirname $(which lz4)))
+    [[ ! $RAPIDJSON_ROOT ]] && RAPIDJSON_ROOT=/usr
+    CLANG_EXECUTABLE=/usr/bin/clang++
+    [[ ! $CLANG_VERSION ]] && CLANG_VERSION=$($CLANG_EXECUTABLE --version | grep version | sed 's|.*version ||')
+  ;;
   *) SONAME=so ;;
 esac
 
+echo "CLANG_VERSION: $CLANG_VERSION"
 # Downloaded by CMake, built, and linked statically (not needed at runtime):
 #   zlib, lz4, brotli
 #
@@ -57,18 +66,25 @@ esac
 
 mkdir -p ./src_tmp
 rsync -a --exclude='**/.git' --delete --delete-excluded "$SOURCEDIR/" ./src_tmp/
+CLANG_VERSION_SHORT=`echo $CLANG_VERSION | sed "s/\.[0-9]*\$//" | sed "s/^v//"`
+CLANG_VERSION_MAIN=`echo $CLANG_VERSION | sed "s/\(\.[0-9]\)*\$//" | sed "s/^v//"`
+sed -i.deleteme -e "s/set(ARROW_LLVM_VERSION \".*\")/set(ARROW_LLVM_VERSION \"$CLANG_VERSION_SHORT\")/" "./src_tmp/cpp/CMakeLists.txt" || true
+sed -i.deleteme -e "s/set(ARROW_LLVM_VERSIONS \".*\")/set(ARROW_LLVM_VERSIONS \"$CLANG_VERSION_SHORT\")/" "./src_tmp/cpp/CMakeLists.txt" || true
+sed -i.deleteme -e "s/set(ARROW_LLVM_VERSIONS/set(ARROW_LLVM_VERSIONS\n    \"$CLANG_VERSION_SHORT\"/" "./src_tmp/cpp/CMakeLists.txt" || true
 
 case $ARCHITECTURE in
   osx*)
    CLANG_EXECUTABLE=/usr/bin/clang
    ;;
   *)
-   CLANG_EXECUTABLE=${CLANG_ROOT}/bin-safe/clang
+   # CLANG_EXECUTABLE=${CLANG_ROOT}/bin-safe/clang
    # this patches version script to hide llvm symbols in gandiva library
    sed -i.deleteme '/^[[:space:]]*extern/ a \ \ \ \ \ \ llvm*; LLVM*;' "./src_tmp/cpp/src/gandiva/symbols.map"
    ;;
 esac
 
+export LDFLAGS=-lpthread
+
 cmake ./src_tmp/cpp                                                                                 \
       ${CMAKE_SHARED_LINKER_FLAGS:+-DCMAKE_SHARED_LINKER_FLAGS="$CMAKE_SHARED_LINKER_FLAGS"}        \
       -DARROW_DEPENDENCY_SOURCE=SYSTEM                                                              \
@@ -111,6 +127,7 @@ cmake ./src_tmp/cpp
       -DARROW_COMPUTE=ON                                                                            \
       -DARROW_BUILD_STATIC=OFF                                                                      \
       -DCMAKE_INSTALL_RPATH_USE_LINK_PATH=ON                                                        \
+      -DARROW_LLVM_VERSIONS=$CLANG_VERSION_SHORT                                                     \
       -DCLANG_EXECUTABLE="$CLANG_EXECUTABLE"
 
 make ${JOBS:+-j $JOBS}
diff --git a/clang.sh b/clang.sh
index f10c33e571..871e753210 100644
--- a/clang.sh
+++ b/clang.sh
@@ -12,6 +12,9 @@ build_requires:
   - ninja
 env:
   LLVM_ROOT: "$CLANG_ROOT" # needed by LLVMAlt
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e
 
diff --git a/cmake.sh b/cmake.sh
index f44f92bc09..b55522f83a 100644
--- a/cmake.sh
+++ b/cmake.sh
@@ -10,8 +10,10 @@ build_requires:
   - alibuild-recipe-tools
 prefer_system: .*
 prefer_system_check: |
-  verge() { [[  "$1" = "`echo -e "$1\n$2" | sort -V | head -n1`" ]]; }
-  type cmake && verge 3.28.1 `cmake --version | sed -e 's/.* //' | cut -d. -f1,2,3`
+  true
+
+#  verge() { [[  "$1" = "`echo -e "$1\n$2" | sort -V | head -n1`" ]]; }
+#  type cmake && verge 3.28.1 `cmake --version | sed -e 's/.* //' | cut -d. -f1,2,3`
 ---
 #!/bin/bash -e
 
diff --git a/common-o2.sh b/common-o2.sh
index a250cb00c2..a6e105ab99 100644
--- a/common-o2.sh
+++ b/common-o2.sh
@@ -22,7 +22,7 @@ esac
 
 cmake $SOURCEDIR 				\
       -DCMAKE_INSTALL_PREFIX=$INSTALLROOT 	\
-      ${BOOST_ROOT:+-DBOOST_ROOT=$BOOST_ROOT} 	\
+      ${BOOST_ROOT:+-DBOOST_ROOT=$BOOST_ROOT -DBoost_NO_BOOST_CMAKE=ON} 	\
       -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
 
 cp ${BUILDDIR}/compile_commands.json ${INSTALLROOT}
diff --git a/curl.sh b/curl.sh
index 0de000f40b..3997305045 100644
--- a/curl.sh
+++ b/curl.sh
@@ -6,6 +6,9 @@ build_requires:
   - "OpenSSL:(?!osx)"
   - CMake
   - alibuild-recipe-tools
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e
 
diff --git a/debuggui.sh b/debuggui.sh
index 9e8f81a65e..aff798438d 100644
--- a/debuggui.sh
+++ b/debuggui.sh
@@ -34,6 +34,11 @@ case $ARCHITECTURE in
       EXTRA_LIBS="-framework CoreFoundation -framework AppKit"
       DEFINES="-DNO_PARALLEL_SORT"
     ;;
+    arch*)
+      DEFINES="-DIMGUI_IMPL_OPENGL_LOADER_GL3W -DTRACY_NO_FILESELECTOR"
+      EXTRA_LIBS="-lGL -ltbb"
+      [[ ! $FREETYPE_ROOT ]] && FREETYPE_ROOT="/usr"
+    ;;
     *) 
       DEFINES="-DIMGUI_IMPL_OPENGL_LOADER_GL3W -DTRACY_NO_FILESELECTOR -DNO_PARALLEL_SORT"
       EXTRA_LIBS="-lGL"
diff --git a/defaults-jw.sh b/defaults-jw.sh
new file mode 100644
index 0000000000..bb244b2490
--- /dev/null
+++ b/defaults-jw.sh
@@ -0,0 +1,42 @@
+env:
+  CFLAGS: -fPIC -O2 -I/usr/include/tirpc
+  CMAKE_BUILD_TYPE: RELWITHDEBINFO
+  CXXFLAGS: -fPIC -O2 -std=c++17 -I/usr/include/tirpc
+  CXXSTD: '17'
+  ENABLE_VMC: 'ON'
+  GEANT4_BUILD_MULTITHREADED: 'ON'
+overrides:
+  AliPhysics:
+    version: '%(commit_hash)s_O2'
+  AliRoot:
+    requires:
+    - ROOT
+    - fastjet:(?!.*ppc64)
+    - GEANT3
+    - GEANT4_VMC
+    - Vc
+    - ZeroMQ
+    - JAliEn-ROOT
+    version: '%(commit_hash)s_O2'
+  cgal:
+    version: 4.12.2
+  fastjet:
+    tag: v3.4.0_1.045-alice1
+  pythia:
+    requires:
+    - lhapdf
+    - boost
+    tag: v8304
+  O2-customization:
+    env:
+      ENABLE_UPGRADES: OFF # Disable detector upgrades in O2
+      BUILD_ANALYSIS: OFF # Disable analysis in O2
+      BUILD_EXAMPLES: OFF # Disable examples in O2
+      ALIBUILD_ENABLE_CUDA: ON
+package: defaults-jw
+version: v1
+
+---
+# This file is included in any build recipe and it's only used to set
+# environment variables. Which file to actually include can be defined by the
+# "--defaults" option of alibuild.
diff --git a/double-conversion.sh b/double-conversion.sh
index 0dde41cda2..62feaafb60 100644
--- a/double-conversion.sh
+++ b/double-conversion.sh
@@ -4,6 +4,9 @@ source: https://github.com/google/double-conversion
 build_requires:
   - CMake
   - "GCC-Toolchain:(?!osx)"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 
 mkdir -p $INSTALLROOT
diff --git a/flatbuffers.sh b/flatbuffers.sh
index 297a31e064..3b1e2e98e8 100644
--- a/flatbuffers.sh
+++ b/flatbuffers.sh
@@ -12,6 +12,7 @@ build_requires:
 cmake "$SOURCEDIR"                          \
       -G 'Unix Makefiles'                   \
       -DFLATBUFFERS_BUILD_TESTS=OFF         \
+      -DFLATBUFFERS_BUILD_CPP17=ON          \
       -DCMAKE_INSTALL_PREFIX="$INSTALLROOT" \
       -DCMAKE_CXX_FLAGS="$CXXFLAGS -Wno-unknown-warning -Wno-unknown-warning-option -Wno-error=unused-but-set-variable"
 # LLVM 15 requires -Wno-error=unused-but-set-variable to compile
diff --git a/googletest.sh b/googletest.sh
index a4bbaeb64f..c083702727 100644
--- a/googletest.sh
+++ b/googletest.sh
@@ -5,6 +5,9 @@ source: https://github.com/google/googletest
 build_requires:
   - "GCC-Toolchain:(?!osx)"
   - CMake
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/sh
 cmake $SOURCEDIR                           \
diff --git a/jalien-root.sh b/jalien-root.sh
index 25e09bf614..350d1902c5 100644
--- a/jalien-root.sh
+++ b/jalien-root.sh
@@ -24,6 +24,9 @@ case $ARCHITECTURE in
         SONAME=dylib
 	[[ ! $OPENSSL_ROOT ]] && OPENSSL_ROOT=$(brew --prefix openssl@3)
 	[[ ! $LIBWEBSOCKETS_ROOT ]] && LIBWEBSOCKETS_ROOT=$(brew --prefix libwebsockets)
+        ;;
+  arch*)
+    [[ ! JSON_C_ROOT ]] && JSON_C_ROOT=/usr
   ;;
 esac
 
diff --git a/jdk.sh b/jdk.sh
index 74b5b542ca..8b9056713e 100644
--- a/jdk.sh
+++ b/jdk.sh
@@ -4,7 +4,7 @@ build_requires:
   - curl
 prefer_system: .*
 prefer_system_check: |
-  [[ $(uname) == Darwin ]] && /usr/libexec/java_home || exit 1; X=$(mktemp -d); cd $X && printf "public class verAliBuild { public static void main(String[] args) { if (Integer.parseInt((System.getProperty(\"java.version\")+\".\").split(\"\\\\\.\")[0]) < 10) System.exit(42); } }" > verAliBuild.java && javac verAliBuild.java && java verAliBuild && rm -rf $X
+  true
 env:
   JAVA_HOME: "$JDK_ROOT/$(cd $JDK_ROOT; ls -1d jdk*/Contents/Home)"
 prepend_path:
diff --git a/json-c.sh b/json-c.sh
index 5f56907683..47f500ba55 100644
--- a/json-c.sh
+++ b/json-c.sh
@@ -5,6 +5,9 @@ source: https://github.com/json-c/json-c
 build_requires:
   - "autotools:(slc6|slc7)"
   - "GCC-Toolchain:(?!osx)"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e
 rsync -a --delete --exclude '**/.git' --delete-excluded $SOURCEDIR/ ./
diff --git a/libtirpc.sh b/libtirpc.sh
index 9927b8fa93..a184e9011d 100644
--- a/libtirpc.sh
+++ b/libtirpc.sh
@@ -5,6 +5,9 @@ source: https://github.com/alisw/libtirpc
 build_requires:
   - "autotools:(slc6|slc7)"
   - "GCC-Toolchain:(?!osx)"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e
 rsync -a --delete --exclude '**/.git' --delete-excluded $SOURCEDIR/ ./
diff --git a/libwebsockets.sh b/libwebsockets.sh
index 52c6cd5743..f91b4d6013 100644
--- a/libwebsockets.sh
+++ b/libwebsockets.sh
@@ -56,6 +56,7 @@ cmake $SOURCEDIR                                                    \
 cmake --build . --target install ${JOBS+-j $JOBS}
 rm -rf $INSTALLROOT/share
 
+
 # Modulefile
 mkdir -p etc/modulefiles
 alibuild-generate-module --lib --bin > etc/modulefiles/$PKGNAME
diff --git a/lz4.sh b/lz4.sh
index 255589d9f2..35df7062ab 100644
--- a/lz4.sh
+++ b/lz4.sh
@@ -8,7 +8,7 @@ build_requires:
   - alibuild-recipe-tools
 prefer_system: ".*"
 prefer_system_check: |
-  printf "#include <lz4.h>\n" | cc -xc -I$(brew --prefix lz4)/include - -c -M 2>&1
+  true
 ---
 
 cmake -DCMAKE_INSTALL_PREFIX=$INSTALLROOT \
diff --git a/o2-customization.sh b/o2-customization.sh
index bd8d52b79f..55f36c8fc5 100644
--- a/o2-customization.sh
+++ b/o2-customization.sh
@@ -2,6 +2,7 @@ package: O2-customization
 version: "v1.0.0"
 env:
   ENABLE_UPGRADES: "ON"
+  BUILD_SIMULATION: "ON"
 valid_defaults:
   - o2
   - o2-dataflow
@@ -9,6 +10,7 @@ valid_defaults:
   - o2-dev-fairroot
   - alo
   - o2-prod
+  - jw
 ---
 # No contents. The only goal of this recipe is to provide customizations to
 # enable / disable features of the O2 builds. This cannot be done in the O2
diff --git a/o2.sh b/o2.sh
index 5d8336f93d..6b8eb54121 100644
--- a/o2.sh
+++ b/o2.sh
@@ -131,6 +131,7 @@ valid_defaults:
   - o2-dev-fairroot
   - alo
   - o2-prod
+  - jw
 ---
 #!/bin/sh
 export ROOTSYS=$ROOT_ROOT
@@ -141,6 +142,7 @@ export ROOTSYS=$ROOT_ROOT
 # maximum safety.
 unset SIMPATH
 
+SONAME=so
 case $ARCHITECTURE in
   osx*)
     # If we preferred system tools, we need to make sure we can pick them up.
@@ -152,6 +154,9 @@ case $ARCHITECTURE in
     [[ ! $GLFW_ROOT ]] && GLFW_ROOT=`brew --prefix glfw`
     [[ ! $FMT_ROOT ]] && FMT_ROOT=`brew --prefix fmt`
   ;;
+  arch*)
+    export PYTHIA_ROOT=/usr
+  ;;
 esac
 
 # This affects only PR checkers
@@ -174,6 +179,10 @@ if [[ ! $CMAKE_GENERATOR && $DISABLE_NINJA != 1 && $DEVEL_SOURCES != $SOURCEDIR
   unset NINJA_BIN
 fi
 
+unset ALIBUILD_ENABLE_CUDA
+export DISABLE_GPU=ON
+export BUILD_SIMULATION=ON
+export Geant3_DIR=`echo ${GEANT3_ROOT}/lib64/Geant3-*`
 unset DYLD_LIBRARY_PATH
 cmake $SOURCEDIR -DCMAKE_INSTALL_PREFIX=$INSTALLROOT                                                      \
       ${CMAKE_GENERATOR:+-G "$CMAKE_GENERATOR"}                                                           \
@@ -205,6 +214,9 @@ cmake $SOURCEDIR -DCMAKE_INSTALL_PREFIX=$INSTALLROOT
       ${CLANG_REVISION:+-DLLVM_LINK_EXECUTABLE="$CLANG_ROOT/bin/llvm-link"}                               \
       ${ITSRESPONSE_ROOT:+-DITSRESPONSE=${ITSRESPONSE_ROOT}}
 # LLVM_ROOT is required for Gandiva
+#      ${BOOST_ROOT:+-DBoost_NO_BOOST_CMAKE=ON}              \
+#     ${BUILD_SIMULATION:+-DBUILD_SIMULATION=$BUILD_SIMULATION}                                                 \
+#     -DGeant3_DIR=$Geant3_DIR                                                             \
 
 cmake --build . -- ${JOBS+-j $JOBS} install
 
diff --git a/o2suite.sh b/o2suite.sh
index e51144ee92..678d4062cf 100644
--- a/o2suite.sh
+++ b/o2suite.sh
@@ -22,6 +22,7 @@ valid_defaults:
   - alo
   - o2-prod
   - o2-ninja
+  - jw
 ---
 #!/bin/bash -ex
 
diff --git a/onnxruntime.sh b/onnxruntime.sh
index 459e20e5a0..c1093c6d41 100644
--- a/onnxruntime.sh
+++ b/onnxruntime.sh
@@ -45,6 +45,8 @@ cmake "$SOURCEDIR/cmake"
       ${FLATBUFFERS_ROOT:+-DFLATBUFFERS_INCLUDE_DIR=${FLATBUFFERS_ROOT}/include}      \
       ${BOOST_ROOT:+-DBOOST_INCLUDE_DIR=${BOOST_ROOT}/include}
 
+file=$(find -name extension.h)
+sed -i 's|<cstddef>|<cstddef>\n#include <cstdint>|' $file
 cmake --build . -- ${JOBS:+-j$JOBS} install
 
 # Modulefile
diff --git a/openssl.sh b/openssl.sh
index 21290545ee..1b5db4e6a4 100644
--- a/openssl.sh
+++ b/openssl.sh
@@ -2,21 +2,9 @@ package: OpenSSL
 version: v1.1.1m
 tag: OpenSSL_1_1_1m
 source: https://github.com/openssl/openssl
-prefer_system: (?!slc5|slc6)
+prefer_system: .*
 prefer_system_check: |
-  #!/bin/bash -e
-  case $(uname) in
-    Darwin) prefix=$(brew --prefix openssl@3); [ -d "$prefix" ] ;;
-    *) prefix= ;;
-  esac
-  cc -x c - ${prefix:+"-I$prefix/include"} -c -o /dev/null <<\EOF
-  #include <openssl/bio.h>
-  #include <openssl/opensslv.h>
-  #if OPENSSL_VERSION_NUMBER < 0x10101000L
-  #error "System's OpenSSL cannot be used: we need OpenSSL >= 1.1.1 for the Python ssl module. We are going to compile our own version."
-  #endif
-  int main() { }
-  EOF
+  true
 build_requires:
   - zlib
   - alibuild-recipe-tools
diff --git a/pythia.sh b/pythia.sh
index c6cd0f43bd..97d29a582d 100644
--- a/pythia.sh
+++ b/pythia.sh
@@ -9,6 +9,9 @@ requires:
 env:
   PYTHIA8DATA: "$PYTHIA_ROOT/share/Pythia8/xmldoc"
   PYTHIA8: "$PYTHIA_ROOT"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e
 rsync -a $SOURCEDIR/ ./
diff --git a/python-modules.sh b/python-modules.sh
index 2dc393192a..050fa9f11d 100644
--- a/python-modules.sh
+++ b/python-modules.sh
@@ -12,6 +12,9 @@ prepend_path:
   # If we need tensorflow-metal to work on Mac during subsequent builds, we
   # must use lib/python$pyver, not lib/python here.
   PYTHONPATH: "$PYTHON_MODULES_ROOT/lib/python/site-packages"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e
 unset VIRTUAL_ENV
@@ -35,10 +38,12 @@ pyver="$(python3 -c 'import sys; print(str(sys.version_info[0]) + "." + str(sys.
 # Install pinned basic requirements for python infrastructure
 echo "$PIP_BASE_REQUIREMENTS" > base-requirements.txt
 python3 -m pip install -IU -r base-requirements.txt
+
 # The above updates pip and setuptools, so install the rest of the packages separately.
 echo "$PIP_REQUIREMENTS" > requirements.txt
 python3 -m pip install -IU -r requirements.txt
 
+
 # Remove useless stuff
 rm -rvf "$INSTALLROOT/share"
 find "$INSTALLROOT" -mindepth 2 -maxdepth 2 \
diff --git a/rapidjson.sh b/rapidjson.sh
index 3150bc97f0..29a6136561 100644
--- a/rapidjson.sh
+++ b/rapidjson.sh
@@ -9,6 +9,9 @@ build_requires:
   - alibuild-recipe-tools
 prepend_path:
   ROOT_INCLUDE_PATH: "$RAPIDJSON_ROOT/include"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 cmake $SOURCEDIR                                                       \
       -G Ninja                                                         \
diff --git a/readout.sh b/readout.sh
index 22339fcd7c..ebd97c68d6 100644
--- a/readout.sh
+++ b/readout.sh
@@ -36,6 +36,9 @@ case $ARCHITECTURE in
         [[ ! $ZEROMQ_ROOT ]] && ZEROMQ_ROOT=$(brew --prefix zeromq)
         [[ ! $FMT_ROOT ]] && FMT_ROOT=`brew --prefix fmt`
     ;;
+  arch*)
+    [[ ! $LZ4_ROOT ]] && LZ4_ROOT=$(dirname $(dirname $(which lz4)))
+  ;;
 esac
 
 cmake $SOURCEDIR                                                         \
diff --git a/root.sh b/root.sh
index 7a7c7b44c5..7acbc4f0ed 100644
--- a/root.sh
+++ b/root.sh
@@ -83,6 +83,9 @@ case $ARCHITECTURE in
     [[ ! $OPENSSL_ROOT ]] && SYS_OPENSSL_ROOT=$(brew --prefix openssl@3)
     [[ ! $LIBPNG_ROOT ]] && LIBPNG_ROOT=$(brew --prefix libpng)
   ;;
+  arch*)
+    export CXXFLAGS="-I/usr/include/tirpc"
+  ;;
 esac
 
 if [[ $ALIEN_RUNTIME_VERSION ]]; then
@@ -120,6 +123,7 @@ else
   # its own XRootD version.
   ROOT_XROOTD_FLAGS='-Dxrootd=OFF'
 fi
+ROOT_XROOTD_FLAGS="-Dxrootd=ON"
 
 unset DYLD_LIBRARY_PATH
 CMAKE_GENERATOR=${CMAKE_GENERATOR:-Ninja}
@@ -169,6 +173,7 @@ cmake $SOURCEDIR
       -Dvdt=OFF                                                                        \
       -Dbuiltin_vdt=OFF                                                                \
       -Dgviz=OFF                                                                       \
+      -Dimt=OFF                                                                        \
       -Dbuiltin_davix=OFF                                                              \
       -Dbuiltin_afterimage=ON                                                          \
       -Dbuiltin_fftw3=OFF                                                              \
diff --git a/vc.sh b/vc.sh
index 606e7bdd70..d3f5e59dd8 100644
--- a/vc.sh
+++ b/vc.sh
@@ -9,6 +9,9 @@ build_requires:
   - alibuild-recipe-tools
 prepend_path:
   ROOT_INCLUDE_PATH: "$VC_ROOT/include"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e
 cmake $SOURCEDIR -DCMAKE_INSTALL_PREFIX=$INSTALLROOT -DBUILD_TESTING=OFF
diff --git a/xercesc.sh b/xercesc.sh
index 5f5568f40d..0c981b4be7 100644
--- a/xercesc.sh
+++ b/xercesc.sh
@@ -7,7 +7,7 @@ build_requires:
   - alibuild-recipe-tools
 prefer_system: ".*"
 prefer_system_check: |
-  pkg-config --atleast-version=3.2.0 xerces-c 2>&1 && printf "#include \"<xercesc/util/PlatformUtils.hpp>\"\nint main(){}" | c++ -xc - -o /dev/null
+  pkg-config --atleast-version=3.2.0 xerces-c 2>&1 && printf "#include <xercesc/util/PlatformUtils.hpp>\nint main(){}" | c++ -xc++ - -o /dev/null
 prepend_path:
   ROOT_INCLUDE_PATH: "$XERCESC_ROOT/include"
   CMAKE_PREFIX_PATH: "$XERCESC_ROOT"
diff --git a/xrootd.sh b/xrootd.sh
index 229693215c..a71affc847 100644
--- a/xrootd.sh
+++ b/xrootd.sh
@@ -15,6 +15,9 @@ build_requires:
   - alibuild-recipe-tools
 prepend_path:
   PYTHONPATH: "${XROOTD_ROOT}/lib/python/site-packages"
+prefer_system: .*
+prefer_system_check: |
+  true
 ---
 #!/bin/bash -e