Building Drake From Source Fails With "ModuleNotFoundError: No module named 'yaml'"

Question

I am following the instructions here: https://drake.mit.edu/from_source.html. I already ran

./setup/mac/install_prereqs.sh

in my python virtualenv (drake-venv) and it succeeded. I then managed to build and run the inclined plane example with Bazel. But trying to build some of the other examples results in errors involving YAML like this:

(drake-venv) benq:acrobot % bazel build acrobot_input --subcommands --verbose_failures --sandbox_debug
INFO: Analyzed target //examples/acrobot:acrobot_input (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
SUBCOMMAND: # //examples/acrobot:acrobot_input_codegen [action 'Action examples/acrobot/gen/acrobot_input.cc', configuration: f8bba554e4e3784a5a24e83c682b75e9b6104059526c94f74d854527a53436a6, execution platform: @local_config_platform//:host]
(cd /private/var/tmp/_bazel_benq/a35a7fa5c4830c980dbc52ab349cb0bc/execroot/drake && \
  exec env - \
  bazel-out/host/bin/tools/vector_gen/lcm_vector_gen '--src=examples/acrobot/acrobot_input_named_vector.yaml' '--out=bazel-out/darwin-opt/bin/examples/acrobot/gen/acrobot_input.cc' '--out=bazel-out/darwin-opt/bin/examples/acrobot/gen/acrobot_input.h' '--include_prefix=drake')
# Configuration: f8bba554e4e3784a5a24e83c682b75e9b6104059526c94f74d854527a53436a6
# Execution platform: @local_config_platform//:host
ERROR: /Users/benq/Documents/drake/examples/acrobot/BUILD.bazel:30:28: Action examples/acrobot/gen/acrobot_input.cc failed: (Exit 1): sandbox-exec failed: error executing command 
  (cd /private/var/tmp/_bazel_benq/a35a7fa5c4830c980dbc52ab349cb0bc/sandbox/darwin-sandbox/176/execroot/drake && \
  exec env - \
    TMPDIR=/var/folders/s0/tfqtn2s54135x0qzt5kxnzs00000gn/T/ \
  /usr/bin/sandbox-exec -f /private/var/tmp/_bazel_benq/a35a7fa5c4830c980dbc52ab349cb0bc/sandbox/darwin-sandbox/176/sandbox.sb /var/tmp/_bazel_benq/install/ebbb2540c6000feeb8873385c487a79c/process-wrapper '--timeout=0' '--kill_delay=15' bazel-out/host/bin/tools/vector_gen/lcm_vector_gen '--src=examples/acrobot/acrobot_input_named_vector.yaml' '--out=bazel-out/darwin-opt/bin/examples/acrobot/gen/acrobot_input.cc' '--out=bazel-out/darwin-opt/bin/examples/acrobot/gen/acrobot_input.h' '--include_prefix=drake')
Traceback (most recent call last):
  File "/private/var/tmp/_bazel_benq/a35a7fa5c4830c980dbc52ab349cb0bc/sandbox/darwin-sandbox/176/execroot/drake/bazel-out/host/bin/tools/vector_gen/lcm_vector_gen.runfiles/drake/tools/vector_gen/lcm_vector_gen.py", line 10, in <module>
    import yaml
ModuleNotFoundError: No module named 'yaml'
Target //examples/acrobot:acrobot_input failed to build
INFO: Elapsed time: 1.059s, Critical Path: 0.58s
INFO: 5 processes: 5 internal.
FAILED: Build did NOT complete successfully

But I'm not sure why this is happening considering that importing yaml in Terminal works:

(drake-venv) benq:acrobot % which python
/Users/benq/Documents/drake/drake-venv/bin/python
(drake-venv) benq:acrobot % python --version
Python 3.9.10
(drake-venv) benq:acrobot % python -c 'import yaml'
(drake-venv) benq:acrobot %

I've already tried reinstalling PyYaml but that didn't help.

Relevant Info:

Operating System: macOS Monterey (12.3)
Architecture: x86_64
Python: Python 3.9.10
Bazel version:

% which bazel; bazel version
/usr/local/bin/bazel
Build label: 5.0.0-homebrew
Build target: bazel-out/darwin-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Tue Jan 1 00:00:00 1980 (315532800)
Build timestamp: 315532800
Build timestamp as int: 315532800

Bazel C++ compiler: Apple clang version 13.1.6 (clang-1316.0.21.2)
Git revision: 06dd087b40

score 1 · Accepted Answer · answered Mar 27 '22 at 02:35

The lcm_vector_gen in the error message is a code-generation tool that's run as part of the build.

It's probably not obeying your which python, but instead using the hard-coded /usr/local/bin/python3.9 from https://github.com/RobotLocomotion/drake/blob/master/tools/py_toolchain/interpreter_paths.bzl.

We don't run or test our builds within a virtual environment, so you've stumbled into a novel situation.

Possibly editing that bzl file linked above (interpreter_paths.bzl), to point MACOS_I386_INTERPRETER_PATH to your venv python (/Users/benq/Documents/drake/drake-venv/bin/python), would fix the error.

Worked after adding `python-config` to the venv: https://stackoverflow.com/questions/42020937/why-pyvenv-does-not-install-python-config — b524, Mar 28 '22 at 13:36

Building Drake From Source Fails With "ModuleNotFoundError: No module named 'yaml'"

1 Answers1