macOS compilation fails

[oceanusxiv]

I understand that this has only been tested on Ubuntu 22.04, and macOS isn't even a particularly well supported target for ROS2, this is more for presenting my findings trying to make this work on a Mac than anything else.

First, the pic_static_library property on Mac isn't set for many static libraries, but this is easily resolved with

rules_ros2/ros2/interfaces.bzl

Line 866 in 91e1b86

if library.pic_static_library == None:

if library.pic_static_library == None and library.static_library == None:

to restore the previous behavior.

After this, we get python linking errors

ERROR: /private/var/tmp/_bazel_xxx/0c6fe4d261a727bb6fbfa1fdc418e921/external/ros2_rcl_interfaces/BUILD.bazel:25:23: Linking external/ros2_rcl_interfaces/builtin_interfaces/libbuiltin_interfaces_s__rosidl_typesupport_c.dylib failed: (Exit 1): sandbox-exec failed: error executing CppLink command 
  (cd /private/var/tmp/_bazel_xxx/0c6fe4d261a727bb6fbfa1fdc418e921/sandbox/darwin-sandbox/97/execroot/com_github_mvukov_rules_ros2 && \
  exec env - \
    PATH=/bin:/usr/bin:/usr/local/bin \
    PWD=/proc/self/cwd \
    TMPDIR=/var/folders/r6/xyz_wzyd5tv_0snr3fmtc3lr0000gn/T/ \
    ZERO_AR_DATE=1 \
  /usr/bin/sandbox-exec -f /private/var/tmp/_bazel_xxx/0c6fe4d261a727bb6fbfa1fdc418e921/sandbox/darwin-sandbox/97/sandbox.sb /var/tmp/_bazel_xxx/install/c235141d88c168b049a191acefbb1f54/process-wrapper '--timeout=0' '--kill_delay=15' '--stats=/private/var/tmp/_bazel_xxx/0c6fe4d261a727bb6fbfa1fdc418e921/sandbox/darwin-sandbox/97/stats.out' external/local_config_cc/cc_wrapper.sh @bazel-out/darwin_arm64-fastbuild/bin/external/ros2_rcl_interfaces/builtin_interfaces/libbuiltin_interfaces_s__rosidl_typesupport_c.dylib-2.params)
Undefined symbols for architecture arm64:
  "_PyCapsule_New", referenced from:
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      ...
  "_PyImport_ImportModule", referenced from:
      _builtin_interfaces__msg__duration__convert_to_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_to_py in _time_s.o
  "_PyLong_AsLong", referenced from:
      _builtin_interfaces__msg__duration__convert_from_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_from_py in _time_s.o
  "_PyLong_AsUnsignedLong", referenced from:
      _builtin_interfaces__msg__duration__convert_from_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_from_py in _time_s.o
  "_PyLong_FromLong", referenced from:
      _builtin_interfaces__msg__duration__convert_to_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_to_py in _time_s.o
  "_PyLong_FromUnsignedLong", referenced from:
      _builtin_interfaces__msg__duration__convert_to_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_to_py in _time_s.o
  "_PyModule_AddObject", referenced from:
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__duration in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      __register_msg_type__msg__time in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
      ...
  "_PyModule_Create2", referenced from:
      _PyInit_builtin_interfaces_s__rosidl_typesupport_c in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
  "_PyObject_CallObject", referenced from:
      _builtin_interfaces__msg__duration__convert_to_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_to_py in _time_s.o
  "_PyObject_GetAttrString", referenced from:
      _builtin_interfaces__msg__duration__convert_from_py in _duration_s.o
      _builtin_interfaces__msg__duration__convert_from_py in _duration_s.o
      _builtin_interfaces__msg__duration__convert_from_py in _duration_s.o
      _builtin_interfaces__msg__duration__convert_from_py in _duration_s.o
      _builtin_interfaces__msg__duration__convert_from_py in _duration_s.o
      _builtin_interfaces__msg__duration__convert_to_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_from_py in _time_s.o
      _builtin_interfaces__msg__time__convert_from_py in _time_s.o
      _builtin_interfaces__msg__time__convert_from_py in _time_s.o
      _builtin_interfaces__msg__time__convert_from_py in _time_s.o
      _builtin_interfaces__msg__time__convert_from_py in _time_s.o
      ...
  "_PyObject_SetAttrString", referenced from:
      _builtin_interfaces__msg__duration__convert_to_py in _duration_s.o
      _builtin_interfaces__msg__duration__convert_to_py in _duration_s.o
      _builtin_interfaces__msg__time__convert_to_py in _time_s.o
      _builtin_interfaces__msg__time__convert_to_py in _time_s.o
  "__Py_Dealloc", referenced from:
      __Py_DECREF in _duration_s.o
      __Py_DECREF in _time_s.o
      __Py_DECREF in _builtin_interfaces_s.ep.rosidl_typesupport_c.o
ld: symbol(s) not found for architecture arm64

So clearly somewhere CPython is not being linked properly, unfortunately I'm not good enough at bazel to really figure out where it went wrong.

[mvukov]

Thanks for looking into this. You can try to fix linking as in https://github.com/pybind/pybind11_bazel/blob/master/build_defs.bzl#L56-L58. If that works, please open a PR with fixes from this discussion.

It's on my TODO list to create a python extension macro as in the repo above...