Inject in the PATH the folder from the CMake exe that invoked the provider if cmake is not found in the PATH

conan_provider.cmake

@@ -388,12 +388,22 @@ function(conan_install)
     # Invoke "conan install" with the provided arguments
     set(CONAN_ARGS ${CONAN_ARGS} -of=${CONAN_OUTPUT_FOLDER})
     message(STATUS "CMake-Conan: conan install ${CMAKE_SOURCE_DIR} ${CONAN_ARGS} ${ARGN}")
+
+
+    # We inject to the PATH the folder where the CMake that invoked the provider lives
+    # so that in case it's not on the system path the conan install does not fail
+    set(_OLD_PATH $ENV{PATH})
+    set(ENV{PATH} "${CMAKE_DIR}:$ENV{PATH}")
+
     execute_process(COMMAND ${CONAN_COMMAND} install ${CMAKE_SOURCE_DIR} ${CONAN_ARGS} ${ARGN} --format=json
                     RESULT_VARIABLE return_code
                     OUTPUT_VARIABLE conan_stdout
                     ERROR_VARIABLE conan_stderr
                     ECHO_ERROR_VARIABLE    # show the text output regardless
                     WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+
+    set(ENV{PATH} "${_OLD_PATH}")
+
     if(NOT "${return_code}" STREQUAL "0")
         message(FATAL_ERROR "Conan install failed='${return_code}'")
     else()
@@ -579,3 +589,6 @@ cmake_language(DEFER DIRECTORY "${CMAKE_SOURCE_DIR}" CALL conan_provide_dependen
 # Configurable variables for Conan profiles
 set(CONAN_HOST_PROFILE "default;auto-cmake" CACHE STRING "Conan host profile")
 set(CONAN_BUILD_PROFILE "default" CACHE STRING "Conan build profile")
+
+get_filename_component(CMAKE_DIR "${CMAKE_COMMAND}" DIRECTORY)
+set(CMAKE_DIR "${CMAKE_DIR}" CACHE INTERNAL "Path where the CMake executable is")

tests/test_smoke.py

@@ -37,6 +37,7 @@ def run(cmd, check=True):
     subprocess.run(cmd, shell=True, check=check)
 
 
+
 @pytest.fixture(scope="session")
 def conan_home_dir(tmp_path_factory):
     """Set up the CONAN_HOME in a temporary directory,
@@ -669,3 +670,29 @@ def test_no_generator_py(self, capfd, basic_cmake_project, resource_path):
         run(f'cmake -S {source_dir} -B {binary_dir} -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES={conan_provider} -DCMAKE_BUILD_TYPE=Release', check=False)
         _, err = capfd.readouterr()
         assert 'Cmake-conan: CMakeDeps generator was not defined in the conanfile' in err
+
+
+class TestInjectCMakeFolderToPath:
+    def test_inject_invoked_path(self, capfd, basic_cmake_project):
+        """
+        Test that we inject the CMake we used to invoke the provider for the Conan builds
+        """
+        source_dir, binary_dir = basic_cmake_project
+
+        # remove hello binaries to make sure we invoke to cmake via Conan
+        run("conan remove hello:*")
+
+        cmake_dir = os.path.dirname(subprocess.check_output(["which", "cmake"]).decode().strip())
+
+        # remove the cmake folder from the path, invoke cmake with the full path and make sure that nothing fails
+        original_path = os.environ["PATH"]
+        modified_path = ":".join([p for p in original_path.split(":") if p != cmake_dir])
+        os.environ["PATH"] = modified_path
+
+        run(f"{cmake_dir}/cmake -S {source_dir} -B {binary_dir} -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES={conan_provider} -DCMAKE_BUILD_TYPE=Release")
+
+        os.environ["PATH"] = original_path
+
+        _, err = capfd.readouterr()
+
+        assert "Built target hello" in err