[libtorch] cannot open source file "torch/torch.h"

C++
1

i am encountering a problem where in my uneducated opinion, the includes should already be included in the cmake file using

target_include_directories(testing PUBLIC "${TORCH_INCLUDE_DIRS}")

but cannot be opened in the .cpp file, that is in the same directory as the cmake file. here are what my files look like:

CMakelists.txt

cmake_minimum_required(VERSION 3.18)

project(testing)

list(APPEND CMAKE_PREFIX_PATH "Downloads/path/to/libtorch")
find_package(Torch REQUIRED)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${TORCH_CXX_FLAGS}")

add_executable(testing test.cpp)
target_link_libraries(testing ${TORCH_LIBRARIES})
target_include_directories(testing PUBLIC "${TORCH_INCLUDE_DIRS}") #does not build without scope keyword
set_property(TARGET testing PROPERTY CXX_STANDARD 17)


if (MSVC) # I am on Visual Studio
  file(GLOB TORCH_DLLS "${TORCH_INSTALL_PREFIX}/lib/*.dll")
  add_custom_command(TARGET testing
                     POST_BUILD
                     COMMAND ${CMAKE_COMMAND} -E copy_if_different
                     ${TORCH_DLLS}
                     $<TARGET_FILE_DIR:testing>)
endif (MSVC)

test.cpp

#include <torch/torch.h>
#include <iostream>

int main() {
	torch::Tensor tensor = torch::rand({ 2, 3 });
	std::cout << tensor << "\n";
}

in test.cpp it tells me " cannot open source file “torch/torch.h” "
CppProperties.json points to the right torch folder and torch.h is present inside. it was explicitly included there as a fix suggested by visual studio, and removing it does not change the outcome

my question is: why would it not be able to open the file? i have tried opening Visual Studio in Administrator mode, and it did not help.
i have searched the internet far and wide, including this forum, stackoverflow and reddit, but i have not found a solution to my problem so far.

2

${TORCH_INCLUDE_DIRS} definition

if(EXISTS "${TORCH_INSTALL_PREFIX}/include")
  set(TORCH_INCLUDE_DIRS
    ${TORCH_INSTALL_PREFIX}/include
    ${TORCH_INSTALL_PREFIX}/include/torch/csrc/api/include)
else()
  set(TORCH_INCLUDE_DIRS
    ${TORCH_INSTALL_PREFIX}/include
    ${TORCH_INSTALL_PREFIX}/include/torch/csrc/api/include)
endif()

i found out that it 100% finds the correct config when building and /include exists (doesnt matter, it would still try), why it does not add the dependencies is beyond me, because if it did it would probably work. it not finding torch/torch.h would indicate that it does not set.

what i found out is that it does not find my python installation during building caffe2 dependencies, but it didnt stop building for some reason. does that matter? if yes, how can i fix that?