Build issue (probably PEBCAK)
Hi,

I'm trying to build this project but unfortunately encounter a build issue. I think I have a correct environment (including the correct commit version of ESP-IDF).

This is the output I have:
```
rdehuyss@ronald-desktop:~/projects/Personal/m5stack/homepoint/build$ cmake -DM5STACK=ON ../
CMake Warning at /home/rdehuyss/.esp/esp-idf/tools/cmake/git_submodules.cmake:44 (message):
  Git submodule components/coap/libcoap is out of date.  Run 'git submodule
  update --init --recursive' to fix.
Call Stack (most recent call first):
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:78 (git_submodule_check)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:160 (__build_get_idf_git_revision)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/idf.cmake:42 (__build_init)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/project.cmake:7 (include)
  CMakeLists.txt:5 (include)


CMake Warning at /home/rdehuyss/.esp/esp-idf/tools/cmake/git_submodules.cmake:44 (message):
  Git submodule components/esp_wifi/lib_esp32 is out of date.  Run 'git
  submodule update --init --recursive' to fix.
Call Stack (most recent call first):
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:78 (git_submodule_check)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:160 (__build_get_idf_git_revision)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/idf.cmake:42 (__build_init)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/project.cmake:7 (include)
  CMakeLists.txt:5 (include)


CMake Warning at /home/rdehuyss/.esp/esp-idf/tools/cmake/git_submodules.cmake:44 (message):
  Git submodule components/esptool_py/esptool is out of date.  Run 'git
  submodule update --init --recursive' to fix.
Call Stack (most recent call first):
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:78 (git_submodule_check)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:160 (__build_get_idf_git_revision)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/idf.cmake:42 (__build_init)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/project.cmake:7 (include)
  CMakeLists.txt:5 (include)


CMake Warning at /home/rdehuyss/.esp/esp-idf/tools/cmake/git_submodules.cmake:44 (message):
  Git submodule components/lwip/lwip is out of date.  Run 'git submodule
  update --init --recursive' to fix.
Call Stack (most recent call first):
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:78 (git_submodule_check)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:160 (__build_get_idf_git_revision)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/idf.cmake:42 (__build_init)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/project.cmake:7 (include)
  CMakeLists.txt:5 (include)


CMake Warning at /home/rdehuyss/.esp/esp-idf/tools/cmake/git_submodules.cmake:44 (message):
  Git submodule components/mbedtls/mbedtls is out of date.  Run 'git
  submodule update --init --recursive' to fix.
Call Stack (most recent call first):
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:78 (git_submodule_check)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:160 (__build_get_idf_git_revision)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/idf.cmake:42 (__build_init)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/project.cmake:7 (include)
  CMakeLists.txt:5 (include)


CMake Warning at /home/rdehuyss/.esp/esp-idf/tools/cmake/git_submodules.cmake:44 (message):
  Git submodule components/mqtt/esp-mqtt is out of date.  Run 'git submodule
  update --init --recursive' to fix.
Call Stack (most recent call first):
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:78 (git_submodule_check)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:160 (__build_get_idf_git_revision)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/idf.cmake:42 (__build_init)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/project.cmake:7 (include)
  CMakeLists.txt:5 (include)


-- ccache will be used for faster builds
-- Project version: c09760c
-- Building ESP-IDF components for target esp32
-- Checking Python dependencies...
Python requirements from /home/rdehuyss/.esp/esp-idf/requirements.txt are satisfied.
CMake Error at /home/rdehuyss/.esp/esp-idf/components/esp32/project_include.cmake:11 (message):
  Internal error, toolchain has not been set correctly by project (or an
  invalid CMakeCache.txt file has been generated somehow)
Call Stack (most recent call first):
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:284 (include)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/build.cmake:449 (__build_process_project_includes)
  /home/rdehuyss/.esp/esp-idf/tools/cmake/project.cmake:315 (idf_build_process)
  CMakeLists.txt:14 (project)


-- Configuring incomplete, errors occurred!
See also "/home/rdehuyss/projects/Personal/m5stack/homepoint/build/CMakeFiles/CMakeOutput.log".
```

My system:
```
rdehuyss@ronald-desktop:~/projects/Personal/m5stack/homepoint/build$ printenv PATH
/home/rdehuyss/.esp/esp-idf/tools:/home/rdehuyss/.esp/xtensa-esp32-elf/bin:/home/rdehuyss/.local/bin:/home/rdehuyss/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
rdehuyss@ronald-desktop:~/projects/Personal/m5stack/homepoint/build$ printenv IDF_PATH
/home/rdehuyss/.esp/esp-idf
rdehuyss@ronald-desktop:~/projects/Personal/m5stack/homepoint/build$ cd $IDF_PATH
rdehuyss@ronald-desktop:~/.esp/esp-idf$ git status
HEAD detached at 02f2e6366
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   components/coap/libcoap (new commits)
	modified:   components/esp_wifi/lib_esp32 (new commits)
	modified:   components/esptool_py/esptool (new commits)
	modified:   components/lwip/lwip (new commits)
	modified:   components/mbedtls/mbedtls (new commits)
	modified:   components/mqtt/esp-mqtt (new commits)

Untracked files:
  (use "git add <file>..." to include in what will be committed)

	components/bt/controller/
	components/bt/host/

```

Any idea what might be wrong?