Fix CMake configuration for bindings source path (#207)

Author: eminyous

.gitignore

@@ -126,6 +126,3 @@ scratch/
 
 # setuptools-scm managed version file
 src/osqp/_version.py
-
-# files that are modified in the build process
-src/osqp/bindings.cpp

CMakeLists.txt

@@ -37,8 +37,8 @@ list(POP_BACK CMAKE_MESSAGE_INDENT)
 FetchContent_MakeAvailable(osqp)
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/bindings.cpp.in
-               ${CMAKE_CURRENT_SOURCE_DIR}/src/bindings.cpp)
-pybind11_add_module(${OSQP_EXT_MODULE_NAME} src/bindings.cpp)
+               ${CMAKE_CURRENT_BINARY_DIR}/src/bindings.cpp)
+pybind11_add_module(${OSQP_EXT_MODULE_NAME} ${CMAKE_CURRENT_BINARY_DIR}/src/bindings.cpp)
 install(TARGETS ${OSQP_EXT_MODULE_NAME} DESTINATION . COMPONENT python)
 
 # TODO: We shouldn't have to do this once the interfaces are set up correctly