Comment on #21210 Installing detectron2 through pants Discussion answered by jsirois @johnathanchiu this project has bad packaging has very specific install instructions you didn't follow. It assumes it will only be installed in a venv that already has torch installed. 1st this is how you self-serve debug, stripping Pants and even Pex away: # Make a fresh venv clean room: :; python3.12 -mvenv debug.venv :; debug.venv/bin/pip -q install -U pip :; debug.venv/bin/pip --version pip 24.1.2 from /home/jsirois/dev/pex-tool/pip/debug.venv/lib/python3.12/site-packages/pip (python 3.12) # Now try to install the thing: :; debug.venv/bin/pip install "detectron2 @ git+https://github.com/facebookresearch/detectron2.git@2a420edb307c9bdf640f036d3b196bed474b8593" Collecting detectron2@ git+https://github.com/facebookresearch/detectron2.git@2a420edb307c9bdf640f036d3b196bed474b8593 Cloning https://github.com/facebookresearch/detectron2.git (to revision 2a420edb307c9bdf640f036d3b196bed474b8593) to /tmp/pip-install-p2tn8kc3/detectron2_6edf3acd472a495c83c88728fc54f5b0 Running command git clone --filter=blob:none --quiet https://github.com/facebookresearch/detectron2.git /tmp/pip-install-p2tn8kc3/detectron2_6edf3acd472a495c83c88728fc54f5b0 Running command git rev-parse -q --verify 'sha^2a420edb307c9bdf640f036d3b196bed474b8593' Running command git fetch -q https://github.com/facebookresearch/detectron2.git 2a420edb307c9bdf640f036d3b196bed474b8593 Resolved https://github.com/facebookresearch/detectron2.git to commit 2a420edb307c9bdf640f036d3b196bed474b8593 Installing build dependencies ... done Getting requirements to build wheel ... error error: subprocess-exited-with-error × Getting requirements to build wheel did not run successfully. │ exit code: 1 ╰─> [20 lines of output] Traceback (most recent call last): File "/home/jsirois/dev/pex-tool/pip/debug.venv/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module> main() File "/home/jsirois/dev/pex-tool/pip/debug.venv/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main json_out['return_val'] = hook(**hook_input['kwargs']) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/home/jsirois/dev/pex-tool/pip/debug.venv/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 118, in get_requires_for_build_wheel return hook(config_settings) ^^^^^^^^^^^^^^^^^^^^^ File "/tmp/pip-build-env-kiwg8s1c/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 327, in get_requires_for_build_wheel return self._get_build_requires(config_settings, requirements=[]) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/tmp/pip-build-env-kiwg8s1c/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 297, in _get_build_requires self.run_setup() File "/tmp/pip-build-env-kiwg8s1c/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 497, in run_setup super().run_setup(setup_script=setup_script) File "/tmp/pip-build-env-kiwg8s1c/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 313, in run_setup exec(code, locals()) File "<string>", line 10, in <module> ModuleNotFoundError: No module named 'torch' [end of output] note: This error originates from a subprocess, and is likely not a problem with pip. error: subprocess-exited-with-error × Getting requirements to build wheel did not run successfully. │ exit code: 1 ╰─> See above for output. note: This error originates from a subprocess, and is likely not a problem with pip. So, from this clean room experiment, it appears the project's

setup.py

tries to import

torch

but there is no

torch

. Let's see: https://github.com/facebookresearch/detectron2/blob/2a420edb307c9bdf640f036d3b196bed474b8593/setup.py#L10-L11 Ok... Well, you can import non-stdlib / non-

setuptools

stuff in a

setup.py

but only if you arrange for it to be present via PEP-518 build-system.requires. That just means slapping down a small

pyproject.toml

that they're missing in that project, like so: jsirois/detectron2@e71aca9 And then: :; debug.venv/bin/pip install "detectron2 @ git+https://github.com/jsirois/detectron2@e71aca907a4b8fdf976af26e47ee3343f86b3147" Collecting detectron2@ git+https://github.com/jsirois/detectron2@e71aca907a4b8fdf976af26e47ee3343f86b3147 Cloning https://github.com/jsirois/detectron2 (to revision e71aca907a4b8fdf976af26e47ee3343f86b3147) to /tmp/pip-install-m1yaltk0/detectron2_4b5670d30f8f49fbaa61af4af665ebd8 Running command git clone --filter=blob:none --quiet https://github.com/jsirois/detectron2 /tmp/pip-install-m1yaltk0/detectron2_4b5670d30f8f49fbaa61af4af665ebd8 Running command git rev-parse -q --verify 'sha^e71aca907a4b8fdf976af26e47ee3343f86b3147' Running command git fetch -q https://github.com/jsirois/detectron2 e71aca907a4b8fdf976af26e47ee3343f86b3147 Running command git checkout -q e71aca907a4b8fdf976af26e47ee3343f86b3147 Resolved https://github.com/jsirois/detectron2 to commit e71aca907a4b8fdf976af26e47ee3343f86b3147 Installing build dependencies ... done Getting requirements to build wheel ... done Preparing metadata (pyproject.toml) ... done ... Building wheels for collected packages: detectron2, fvcore, antlr4-python3-runtime Building wheel for detectron2 (pyproject.toml) ... done Created wheel for detectron2: filename=detectron2-0.6-cp312-cp312-linux_x86_64.whl size=5972440 sha256=3e24aaa61415a4e23ea6cc950d7093d6ab0082241826c7aad136e5a630e9bbc1 Stored in directory: /home/jsirois/.cache/pip/wheels/98/a2/f6/f6014a2b0521d0dd908770f84dc19ce3272959e48db75ae2fa Building wheel for fvcore (pyproject.toml) ... done Created wheel for fvcore: filename=fvcore-0.1.5.post20221221-py3-none-any.whl size=61398 sha256=df1de2fe08cab8df8d4164a13d3a5b1f34a34ecdbb0dd4ef21321a6cd43236e4 Stored in directory: /home/jsirois/.cache/pip/wheels/ed/9f/a5/e4f5b27454ccd4596bd8b62432c7d6b1ca9fa22aef9d70a16a Building wheel for antlr4-python3-runtime (pyproject.toml) ... done Created wheel for antlr4-python3-runtime: filename=antlr4_python3_runtime-4.9.3-py3-none-any.whl size=144553 sha256=56a9ce77cd1cf8840a2a9935625dfa9df8d66d83242a77b71cc3d4227ee286be Stored in directory: /home/jsirois/.cache/pip/wheels/1f/be/48/13754633f1d08d1fbfc60d5e80ae1e5d7329500477685286cd Successfully built detectron2 fvcore antlr4-python3-runtime Installing collected packages: antlr4-python3-runtime, tqdm, termcolor, tensorboard-data-server, tabulate, six, setuptools, pyyaml, pyparsing, protobuf, portalocker, platformdirs, Pillow, pathspec, packaging, numpy, mypy-extensions, MarkupSafe, markdown, kiwisolver, grpcio, fonttools, cycler, cloudpickle, click, absl-py, yacs, werkzeug, python-dateutil, omegaconf, iopath, contourpy, black, tensorboard, matplotlib, hydra-core, fvcore, pycocotools, detectron2 Successfully installed MarkupSafe-2.1.5 Pillow-10.4.0 absl-py-2.1.0 antlr4-python3-runtime-4.9.3 black-24.4.2 click-8.1.7 cloudpickle-3.0.0 contourpy-1.2.1 cycler-0.12.1 detectron2-0.6 fonttools-4.53.1 fvcore-0.1.5.post20221221 grpcio-1.65.1 hydra-core-1.3.2 iopath-0.1.9 kiwisolver-1.4.5 markdown-3.6 matplotlib-3.9.1 mypy-extensions-1.0.0 numpy-2.0.1 omegaconf-2.3.0 packaging-24.1 pathspec-0.12.1 platformdirs-4.2.2 portalocker-2.10.1 protobuf-4.25.4 pycocotools-2.0.8 pyparsing-3.1.2 python-dateutil-2.9.0.post0 pyyaml-6.0.1 setuptools-71.1.0 six-1.16.0 tabulate-0.9.0 tensorboard-2.17.0 tensorboard-data-server-0.7.2 termcolor-… pantsbuild/pants