Automatically put torch in CMAKE_PREFIX_PATH so users/scripts don't have to (#8474)

Removed all explicit setting of CMAKE_PREFIX_PATH to the torch directory in favor of automatically doing it when we find_package(Torch). Hat tip to @huydhn for showing the way to only find torch once.

Author: swolchok

.ci/scripts/build_llama_android.sh

@@ -14,7 +14,6 @@ if [[ -z "${PYTHON_EXECUTABLE:-}" ]]; then
   PYTHON_EXECUTABLE=python3
 fi
 which "${PYTHON_EXECUTABLE}"
-CMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')"
 
 install_executorch_and_backend_lib() {
   echo "Installing executorch and xnnpack backend"
@@ -28,7 +27,6 @@ install_executorch_and_backend_lib() {
     -DANDROID_ABI="${ANDROID_ABI}" \
     -DCMAKE_INSTALL_PREFIX=cmake-android-out \
     -DCMAKE_BUILD_TYPE=Release \
-    -DCMAKE_PREFIX_PATH="${CMAKE_PREFIX_PATH}" \
     -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
     -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \
     -DEXECUTORCH_BUILD_EXTENSION_TENSOR=ON \
@@ -54,7 +52,6 @@ build_llama_runner() {
     -DEXECUTORCH_BUILD_KERNELS_OPTIMIZED=ON \
     -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON \
     -DEXECUTORCH_BUILD_KERNELS_CUSTOM=ON \
-    -DCMAKE_PREFIX_PATH="${CMAKE_PREFIX_PATH}" \
     -Bcmake-android-out/examples/models/llama examples/models/llama
 
     cmake --build cmake-android-out/examples/models/llama -j4 --config Release

.ci/scripts/test_llama.sh

@@ -154,7 +154,6 @@ cmake_install_executorch_libraries() {
     rm -rf cmake-out
     retry cmake \
         -DCMAKE_INSTALL_PREFIX=cmake-out \
-        -DCMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')" \
         -DCMAKE_BUILD_TYPE="$CMAKE_BUILD_TYPE" \
         -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
         -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \

.ci/scripts/test_llava.sh

@@ -31,7 +31,6 @@ NPROC=8
 if hash nproc &> /dev/null; then NPROC=$(nproc); fi
 
 python_lib=$($PYTHON_EXECUTABLE -c 'from distutils.sysconfig import get_python_lib; print(get_python_lib())')
-CMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')"
 EXECUTORCH_COMMON_CMAKE_ARGS="                      \
         -DCMAKE_INSTALL_PREFIX=${BUILD_DIR}         \
         -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}      \
@@ -48,7 +47,6 @@ EXECUTORCH_COMMON_CMAKE_ARGS="                      \
 cmake_install_executorch_libraries() {
     cmake                               \
         ${EXECUTORCH_COMMON_CMAKE_ARGS} \
-        "-DCMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}" \
         -B${BUILD_DIR} .
 
     cmake --build ${BUILD_DIR} -j${NPROC} --target install --config ${CMAKE_BUILD_TYPE}
@@ -59,7 +57,6 @@ cmake_install_executorch_libraries_for_android() {
         -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK/build/cmake/android.toolchain.cmake \
         -DANDROID_ABI=arm64-v8a                                                 \
         ${EXECUTORCH_COMMON_CMAKE_ARGS}                                         \
-        "-DCMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}" \
         -B${BUILD_DIR} .
 
     cmake --build ${BUILD_DIR} -j${NPROC} --target install --config ${CMAKE_BUILD_TYPE}
@@ -80,7 +77,7 @@ cmake_build_llava_runner() {
 
     cmake                                 \
         ${LLAVA_COMMON_CMAKE_ARGS}        \
-        -DCMAKE_PREFIX_PATH="$python_lib;${CMAKE_PREFIX_PATH}" \
+        -DCMAKE_PREFIX_PATH="$python_lib" \
         -B${BUILD_DIR}/${dir}             \
         ${dir}
 
@@ -96,7 +93,7 @@ cmake_build_llava_runner_for_android() {
         -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK/build/cmake/android.toolchain.cmake \
         -DANDROID_ABI=arm64-v8a                                                 \
         ${LLAVA_COMMON_CMAKE_ARGS}                                              \
-        -DCMAKE_PREFIX_PATH="$python_lib;${CMAKE_PREFIX_PATH}"                  \
+        -DCMAKE_PREFIX_PATH="$python_lib"                  \
         -DLLAVA_RUNNER_NO_TORCH_DUMMY_IMAGE=ON                                  \
         -B${BUILD_DIR}/${dir}                                                   \
         ${dir}

.ci/scripts/test_model.sh

@@ -50,12 +50,10 @@ prepare_artifacts_upload() {
 
 build_cmake_executor_runner() {
   echo "Building executor_runner"
-  CMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')"
   rm -rf ${CMAKE_OUTPUT_DIR}
   cmake -DCMAKE_BUILD_TYPE=Debug \
       -DEXECUTORCH_BUILD_KERNELS_OPTIMIZED=ON \
       -DPYTHON_EXECUTABLE="$PYTHON_EXECUTABLE" \
-      -DCMAKE_PREFIX_PATH="$CMAKE_PREFIX_PATH" \
       -B${CMAKE_OUTPUT_DIR} .
 
   cmake --build ${CMAKE_OUTPUT_DIR} -j4 --config Debug
@@ -100,14 +98,12 @@ test_model() {
 
 build_cmake_xnn_executor_runner() {
   echo "Building xnn_executor_runner"
-  CMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')"
 
   (rm -rf ${CMAKE_OUTPUT_DIR} \
     && mkdir ${CMAKE_OUTPUT_DIR} \
     && cd ${CMAKE_OUTPUT_DIR} \
     && retry cmake -DCMAKE_BUILD_TYPE=Release \
       -DEXECUTORCH_BUILD_XNNPACK=ON \
-      -DCMAKE_PREFIX_PATH="$CMAKE_PREFIX_PATH" \
       -DPYTHON_EXECUTABLE="$PYTHON_EXECUTABLE" ..)
 
   cmake --build ${CMAKE_OUTPUT_DIR} -j4

.ci/scripts/test_phi_3_mini.sh

@@ -22,10 +22,8 @@ NPROC=8
 if hash nproc &> /dev/null; then NPROC=$(nproc); fi
 
 cmake_install_executorch_libraries() {
-  CMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')"
   cmake -DPYTHON_EXECUTABLE=python \
       -DCMAKE_INSTALL_PREFIX=${BUILD_DIR} \
-      -DCMAKE_PREFIX_PATH="${CMAKE_PREFIX_PATH}" \
       -DEXECUTORCH_ENABLE_LOGGING=1 \
       -DCMAKE_BUILD_TYPE=${BUILD_TYPE} \
       -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
@@ -41,10 +39,8 @@ cmake_install_executorch_libraries() {
 }
 
 cmake_build_phi_3_mini() {
-  CMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')"
   cmake -DPYTHON_EXECUTABLE=$PYTHON_EXECUTABLE \
       -DCMAKE_INSTALL_PREFIX=${BUILD_DIR} \
-      -DCMAKE_PREFIX_PATH="${CMAKE_PREFIX_PATH}" \
       -DCMAKE_BUILD_TYPE=${BUILD_TYPE} \
       -DEXECUTORCH_BUILD_KERNELS_CUSTOM=ON \
       -DEXECUTORCH_BUILD_KERNELS_OPTIMIZED=ON \

.ci/scripts/test_quantized_aot_lib.sh

@@ -16,13 +16,10 @@ CMAKE_OUTPUT_DIR=cmake-out
 
 build_cmake_quantized_aot_lib() {
   echo "Building quantized aot lib"
-  SITE_PACKAGES="$(${PYTHON_EXECUTABLE} -c 'from distutils.sysconfig import get_python_lib; print(get_python_lib())')"
-  CMAKE_PREFIX_PATH="${SITE_PACKAGES}/torch"
   (rm -rf ${CMAKE_OUTPUT_DIR} \
     && mkdir ${CMAKE_OUTPUT_DIR} \
     && cd ${CMAKE_OUTPUT_DIR} \
     && retry cmake -DCMAKE_BUILD_TYPE=Release \
-      -DCMAKE_PREFIX_PATH="$CMAKE_PREFIX_PATH" \
       -DEXECUTORCH_BUILD_KERNELS_QUANTIZED_AOT=ON \
       -DPYTHON_EXECUTABLE="$PYTHON_EXECUTABLE" ..)
 

.ci/scripts/utils.sh

@@ -136,7 +136,6 @@ cmake_install_executorch_lib() {
   clean_executorch_install_folders
   retry cmake -DBUCK2="$BUCK" \
           -DCMAKE_INSTALL_PREFIX=cmake-out \
-          -DCMAKE_PREFIX_PATH="$($PYTHON_EXECUTABLE -c 'import torch as _; print(_.__path__[0])')" \
           -DCMAKE_BUILD_TYPE=Release \
           -DPYTHON_EXECUTABLE="$PYTHON_EXECUTABLE" \
           -Bcmake-out .

.github/workflows/trunk.yml

@@ -394,7 +394,6 @@ jobs:
         rm -rf cmake-out
         cmake \
             -DCMAKE_INSTALL_PREFIX=cmake-out \
-            -DCMAKE_PREFIX_PATH="$(python -c 'import torch as _; print(_.__path__[0])')" \
             -DCMAKE_BUILD_TYPE=Release \
             -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
             -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \
@@ -412,7 +411,6 @@ jobs:
         cmake \
             -DCMAKE_INSTALL_PREFIX=cmake-out \
             -DCMAKE_BUILD_TYPE=Release \
-            -DCMAKE_PREFIX_PATH="$(python -c 'import torch as _; print(_.__path__[0])')" \
             -DEXECUTORCH_BUILD_KERNELS_CUSTOM=ON \
             -DEXECUTORCH_BUILD_KERNELS_OPTIMIZED=ON \
             -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON \

CMakeLists.txt

@@ -761,9 +761,7 @@ if(EXECUTORCH_BUILD_PYBIND)
   endif()
 
   # find pytorch lib, to allow pybind to take at::Tensor as input/output
-  if(NOT TARGET torch)
-    find_package(Torch CONFIG REQUIRED)
-  endif()
+  find_package_torch()
   find_library(
     TORCH_PYTHON_LIBRARY torch_python PATHS "${TORCH_INSTALL_PREFIX}/lib"
   )

backends/arm/scripts/build_quantized_ops_aot_lib.sh

@@ -11,9 +11,6 @@ build_type="Release"
 
 build_type=${1:-$build_type}
 
-SITE_PACKAGES="$(python3 -c 'from distutils.sysconfig import get_python_lib; print(get_python_lib())')"
-CMAKE_PREFIX_PATH="${SITE_PACKAGES}/torch"
-
 echo "--------------------------------------------------------------------------------"
 echo "Build .so library to register quant ops with AoT flow ${build_type} into '$(echo $(pwd))/cmake-out-aot-lib'"
 echo "--------------------------------------------------------------------------------"
@@ -23,7 +20,6 @@ echo "--------------------------------------------------------------------------
 rm -f cmake-out-aot-lib/CMakeCache.txt
 
 CXXFLAGS="-fno-exceptions -fno-rtti" cmake \
-    -DCMAKE_PREFIX_PATH="$CMAKE_PREFIX_PATH"    \
     -DCMAKE_BUILD_TYPE=${build_type}            \
     -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON      \
     -DEXECUTORCH_BUILD_KERNELS_QUANTIZED_AOT=ON \

build/Codegen.cmake

@@ -9,6 +9,8 @@
 
 # Selective build. See codegen/tools/gen_oplist.py for how to use these
 # arguments.
+include(${EXECUTORCH_ROOT}/build/Utils.cmake)
+
 function(gen_selected_ops)
   set(arg_names LIB_NAME OPS_SCHEMA_YAML ROOT_OPS INCLUDE_ALL_OPS)
   cmake_parse_arguments(GEN "" "" "${arg_names}" ${ARGN})
@@ -145,18 +147,13 @@ function(gen_custom_ops_aot_lib)
     ${_out_dir}/RegisterCPUCustomOps.cpp ${_out_dir}/RegisterSchema.cpp
     ${_out_dir}/CustomOpsNativeFunctions.h "${GEN_KERNEL_SOURCES}"
   )
-  # Find `Torch`.
-  if(NOT TARGET torch)
-    find_package(Torch REQUIRED)
-  endif()
+  find_package_torch()
   # This lib uses ATen lib, so we explicitly enable rtti and exceptions.
   target_compile_options(${GEN_LIB_NAME} PRIVATE -frtti -fexceptions)
   target_compile_definitions(${GEN_LIB_NAME} PRIVATE USE_ATEN_LIB=1)
   include_directories(${TORCH_INCLUDE_DIRS})
   target_link_libraries(${GEN_LIB_NAME} PRIVATE torch)
 
-  include(${EXECUTORCH_ROOT}/build/Utils.cmake)
-
   target_link_options_shared_lib(${GEN_LIB_NAME})
   if(TARGET portable_lib)
     target_link_libraries(${GEN_LIB_NAME} PRIVATE portable_lib)

build/Utils.cmake

@@ -328,21 +328,61 @@ function(resolve_python_executable)
   endif()
 endfunction()
 
-# find_package(Torch CONFIG REQUIRED) replacement for targets that
-# have a header-only Torch dependency. Because find_package sets
-# variables in the parent scope, we use a macro to preserve this
-# rather than maintaining our own list of those variables.
+# find_package(Torch CONFIG REQUIRED) replacement for targets that have a
+# header-only Torch dependency. Because find_package sets variables in the
+# parent scope, we use a macro to preserve this rather than maintaining our own
+# list of those variables.
 macro(find_package_torch_headers)
-  # We cannot simply use CMAKE_FIND_ROOT_PATH_BOTH, because that does
-  # not propagate into TorchConfig.cmake.
+  # We cannot simply use CMAKE_FIND_ROOT_PATH_BOTH, because that does not
+  # propagate into TorchConfig.cmake.
   foreach(mode_kind IN ITEMS PACKAGE LIBRARY INCLUDE)
-    set(OLD_CMAKE_FIND_ROOT_PATH_MODE_${mode_kind} ${CMAKE_FIND_ROOT_PATH_MODE_${mode_kind}})
+    set(OLD_CMAKE_FIND_ROOT_PATH_MODE_${mode_kind}
+        ${CMAKE_FIND_ROOT_PATH_MODE_${mode_kind}}
+    )
     set(CMAKE_FIND_ROOT_PATH_MODE_${mode_kind} BOTH)
   endforeach()
+  find_package_torch()
+  foreach(mode_kind IN ITEMS PACKAGE LIBRARY INCLUDE)
+    set(CMAKE_FIND_ROOT_PATH_MODE_${mode_kind}
+        ${OLD_CMAKE_FIND_ROOT_PATH_MODE_${mode_kind}}
+    )
+  endforeach()
+endmacro()
+
+# Add the Torch CMake configuration to CMAKE_PREFIX_PATH so that find_package
+# can find Torch.
+function(add_torch_to_cmake_prefix_path)
+  if(NOT PYTHON_EXECUTABLE)
+    resolve_python_executable()
+  endif()
+  execute_process(
+    COMMAND "${PYTHON_EXECUTABLE}" -c
+            "import torch as _; print(_.__path__[0], end='')"
+    OUTPUT_VARIABLE _tmp_torch_path
+    ERROR_VARIABLE _tmp_torch_path_error
+    RESULT_VARIABLE _tmp_torch_path_result COMMAND_ECHO STDERR
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+  if(NOT _tmp_torch_path_result EQUAL 0)
+    message("Error while adding torch to CMAKE_PREFIX_PATH. "
+            "Exit code: ${_tmp_torch_path_result}"
+    )
+    message("Output:\n${_tmp_torch_path}")
+    message(FATAL_ERROR "Error:\n${_tmp_torch_path_error}")
+  endif()
+  list(APPEND CMAKE_PREFIX_PATH "${_tmp_torch_path}")
+  set(CMAKE_PREFIX_PATH
+      "${CMAKE_PREFIX_PATH}"
+      PARENT_SCOPE
+  )
+endfunction()
+
+# Replacement for find_package(Torch CONFIG REQUIRED); sets up CMAKE_PREFIX_PATH
+# first and only does the find once. If you have a header-only Torch dependency,
+# use find_package_torch_headers instead!
+macro(find_package_torch)
   if(NOT TARGET torch)
+    add_torch_to_cmake_prefix_path()
     find_package(Torch CONFIG REQUIRED)
   endif()
-  foreach(mode_kind IN ITEMS PACKAGE LIBRARY INCLUDE)
-    set(CMAKE_FIND_ROOT_PATH_MODE_${mode_kind} ${OLD_CMAKE_FIND_ROOT_PATH_MODE_${mode_kind}})
-  endforeach()
 endmacro()

build/build_android_llm_demo.sh

@@ -11,7 +11,6 @@ if [[ -z "${PYTHON_EXECUTABLE:-}" ]]; then
   PYTHON_EXECUTABLE=python3
 fi
 which "${PYTHON_EXECUTABLE}"
-CMAKE_PREFIX_PATH="$(python3 -c 'import torch as _; print(_.__path__[0])')"
 
 build_jar() {
   pushd extension/android
@@ -42,7 +41,6 @@ build_android_native_library() {
   fi
 
   cmake . -DCMAKE_INSTALL_PREFIX="${CMAKE_OUT}" \
-    -DCMAKE_PREFIX_PATH="${CMAKE_PREFIX_PATH}" \
     -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK}/build/cmake/android.toolchain.cmake" \
     -DANDROID_ABI="${ANDROID_ABI}" \
     -DANDROID_PLATFORM=android-26 \
@@ -76,7 +74,6 @@ build_android_native_library() {
     -DANDROID_ABI="${ANDROID_ABI}" \
     -DANDROID_PLATFORM=android-26 \
     -DCMAKE_INSTALL_PREFIX="${CMAKE_OUT}" \
-    -DCMAKE_PREFIX_PATH="${CMAKE_PREFIX_PATH}" \
     -DEXECUTORCH_ENABLE_LOGGING=ON \
     -DEXECUTORCH_LOG_LEVEL=Info \
     -DCMAKE_FIND_ROOT_PATH_MODE_PACKAGE=BOTH \

build/build_apple_frameworks.sh

@@ -150,7 +150,6 @@ cmake_build() {
     mkdir "$platform" && cd "$platform" || exit 1
     cmake "$SOURCE_ROOT_DIR" -G Xcode \
         -DCMAKE_BUILD_TYPE="$MODE" \
-        -DCMAKE_PREFIX_PATH="$($PYTHON -c 'import torch as _; print(_.__path__[0])')" \
         -DCMAKE_TOOLCHAIN_FILE="$TOOLCHAIN" \
         -DCMAKE_XCODE_ATTRIBUTE_CLANG_CXX_LANGUAGE_STANDARD="c++17" \
         -DCMAKE_XCODE_ATTRIBUTE_CLANG_CXX_LIBRARY="libc++" \

docs/source/executorch-arm-delegate-tutorial.md

@@ -228,16 +228,13 @@ python3 -m examples.arm.aot_arm_compiler --model_name="add" --delegate
 Before generating the `.pte` file for delegated quantized networks like MobileNetV2, we need to build the `quantized_ops_aot_lib`
 
 ```bash
-SITE_PACKAGES="$(python3 -c 'from distutils.sysconfig import get_python_lib; print(get_python_lib())')"
-CMAKE_PREFIX_PATH="${SITE_PACKAGES}/torch"
 
 cd <executorch_root_dir>
 mkdir -p cmake-out-aot-lib
 cmake -DCMAKE_BUILD_TYPE=Release \
     -DEXECUTORCH_BUILD_XNNPACK=OFF \
     -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON \
     -DEXECUTORCH_BUILD_KERNELS_QUANTIZED_AOT=ON \
-    -DCMAKE_PREFIX_PATH="$CMAKE_PREFIX_PATH" \
     -DPYTHON_EXECUTABLE=python3 \
 -Bcmake-out-aot-lib \
     "${et_root_dir}"

examples/models/llava/CMakeLists.txt

@@ -79,7 +79,7 @@ if(LLAVA_RUNNER_NO_TORCH_DUMMY_IMAGE)
   add_definitions(-DLLAVA_NO_TORCH_DUMMY_IMAGE=1)
   message("Buidling the runner without Torch, feeding a dummy image!")
 else()
-  find_package(Torch CONFIG REQUIRED)
+  find_package_torch()
 endif()
 
 #

examples/portable/custom_ops/test_custom_ops.sh

@@ -53,8 +53,7 @@ get_shared_lib_ext() {
 
 test_cmake_custom_op_2() {
   local model_name='custom_ops_2'
-  SITE_PACKAGES="$(${PYTHON_EXECUTABLE} -c 'from distutils.sysconfig import get_python_lib; print(get_python_lib())')"
-  CMAKE_PREFIX_PATH="$PWD/cmake-out/lib/cmake/ExecuTorch;${SITE_PACKAGES}/torch"
+  CMAKE_PREFIX_PATH="$PWD/cmake-out/lib/cmake/ExecuTorch"
 
   local example_dir=examples/portable/custom_ops
   local build_dir=cmake-out/${example_dir}

examples/xnnpack/quantization/test_quantize.sh

@@ -44,8 +44,6 @@ test_buck2_quantization() {
 
 test_cmake_quantization() {
   echo "Building quantized ops shared library"
-  SITE_PACKAGES="$(${PYTHON_EXECUTABLE} -c 'from distutils.sysconfig import get_python_lib; print(get_python_lib())')"
-  CMAKE_PREFIX_PATH="${SITE_PACKAGES}/torch"
 
   clean_executorch_install_folders
 
@@ -56,7 +54,6 @@ test_cmake_quantization() {
       -DEXECUTORCH_BUILD_XNNPACK="$EXECUTORCH_BUILD_XNNPACK" \
       -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON \
       -DEXECUTORCH_BUILD_KERNELS_QUANTIZED_AOT=ON \
-      -DCMAKE_PREFIX_PATH="$CMAKE_PREFIX_PATH" \
       -DPYTHON_EXECUTABLE="$PYTHON_EXECUTABLE" ..)
 
   cmake --build cmake-out -j4

extension/llm/custom_ops/CMakeLists.txt

@@ -69,9 +69,7 @@ install(TARGETS custom_ops DESTINATION lib)
 
 if(EXECUTORCH_BUILD_KERNELS_CUSTOM_AOT)
   # Add a AOT library
-  if(NOT TARGET torch)
-    find_package(Torch CONFIG REQUIRED)
-  endif()
+  find_package_torch()
   add_library(
     custom_ops_aot_lib SHARED
     ${_custom_ops__srcs}

extension/llm/export/quantizer_lib.py

@@ -107,10 +107,8 @@ def check_embedding_byte_registered():
                 raise RuntimeError(
                     "Need to specify shared library path to register quantized ops (and their out variants) into EXIR.\n"
                     "Follow the following steps to build the needed lib via cmake.\n"
-                    'Use `python -c "import torch as _; print(_.__path__)"` to find where torch package is installed.\n'
-                    "Set that as TORCH_PACKAGE_DIR.\n"
                     "Then from root executorch dir do the following:\n"
-                    "rm -rf cmake-out && mkdir cmake-out && (cd cmake-out && cmake -DBUCK2=<path-to-buck2> -DCMAKE_PREFIX_PATH=$TORCH_PACKAGE_DIR -DEXECUTORCH_BUILD_KERNELS_QUANTIZED_AOT=ON ..) && cmake --build . -j16\n"
+                    "rm -rf cmake-out && mkdir cmake-out && (cd cmake-out && cmake -DBUCK2=<path-to-buck2> -DEXECUTORCH_BUILD_KERNELS_QUANTIZED_AOT=ON ..) && cmake --build . -j16\n"
                     'To find the location of the lib: find cmake-out -name "libquantized_ops_aot_lib*"\n'
                     "Then specify the said library via -s <path to libquantized_ops_aot_lib.so\n"
                 )