pybind: Should restore fork's latest commit in workspace pending mac fix

[EricCousineau-TRI]

See: #14046 (comment)

This was reproducible on our macsim machine.

@jamiesnape I will try this briefly. If I can't make this work today, can I ask you to put this at the top of your pydrake queue for the next two weeks?

---

UPDATE: Plan of attack:

• drake_cmake_installed: Address upstream's -fvisibility settings drake-external-examples#187 File drake-external-examples PR to explicitly set default visibility to -fvisibility=default. This should merge first.
• Restore "workspace: Update pybind11 fork to latest commit" #14048 File drake restore PR afterwards.

[jamiesnape]

So this issue is restoring the fork or fixing the underlying Mac issue?

[EricCousineau-TRI]

Fixing the underlying Mac issue for building in CMake that causes the RTTI mismatch, most likely due to some visibility changes that came from the fork updates.
Not sure if it requires a change to our fork, or just a change in downstream.

(RobotLocomotion/pybind11 itself is unchanged at present, and I don't think we should revert anything there)

[EricCousineau-TRI]

FTR On macsim, I am using this drake-external-examples setup:
https://github.com/RobotLocomotion/drake-external-examples/blob/8a53b4c8df534fcc02f557d1579636dd16795151/drake_cmake_installed/src/simple_bindings/CMakeLists.txt

I confirmed that drake @ 690a7ea works (post-revert), and drake @ 0cc01f0 (pre-revert) reprodues the error:

cd .../drake
bazel run //:install -- /tmp/drake

cd .../bazel-external-examples/drake_cmake_installed
mkdir build && cd build
cmake -DCMAKE_PREFIX_PATH=/tmp/drake ..
cd src/simple_bindings/
make && ctest -V -R

[jamiesnape]

Ok, can you update the title to match?

[EricCousineau-TRI]

Done.

My money's on some change from upstream's CMake in pybind11Tools or pybind11Config:
RobotLocomotion/pybind11@58a368ea8#diff-8cb32abb960df57289d52b400092e31d

[EricCousineau-TRI]

Yuppers. It looks like pybind/pybind11@97aa54fefa is the culprit.
I had stripped it out (accidentally?) before, and restored it when I carte-blanch took in upstream's changes.

Here's the patch-fix for drake-external-examples:

diff --git a/drake_cmake_installed/src/simple_bindings/CMakeLists.txt b/drake_cmake_installed/src/simple_bindings/CMakeLists.txt
index 1fde04b..d8530c3 100644
--- a/drake_cmake_installed/src/simple_bindings/CMakeLists.txt
+++ b/drake_cmake_installed/src/simple_bindings/CMakeLists.txt
@@ -33,7 +33,14 @@
 find_package(pybind11 CONFIG REQUIRED)
 
 pybind11_add_module(simple_bindings MODULE simple_bindings.cc)
-target_link_libraries(simple_bindings PUBLIC drake::drake pybind11::module)
+target_link_libraries(simple_bindings PUBLIC drake::drake)
+# N.B. `pybind11_add_module` normally sets the default visibility to "hidden"
+# to avoid warnings. However, we generally take care in Drake to avoid mixing
+# hidden and public symbols, so we should we confidently re-enable this
+# setting.
+# For more information, see:
+# https://github.com/RobotLocomotion/drake/issues/14047
+set_target_properties(simple_bindings PROPERTIES CXX_VISIBILITY_PRESET "default")
 
 add_test(NAME simple_bindings_test COMMAND
     "${PYTHON_EXECUTABLE}" "${CMAKE_CURRENT_SOURCE_DIR}/simple_bindings_test.py")

My desire is to leave upstream's CMake logic as untouched as possible. I think just propogating this specific CXX_VISIBILITY_PRESET post-fix should be fine.

[EricCousineau-TRI]

Confirmed that this patch works on both drake @ 690a7ea and drake @ 0cc01f0. Will update overview with plan of attack.

EDIT: Done.

[EricCousineau-TRI]

Filed upstream issue to pybind11: pybind/pybind11#2479