Installation fails immediately: ModuleNotFoundError: No module named 'torch'

[Brennanzuz]

The installation instructions is incomplete, and causes a quick error:

git clone https://github.com/flashinfer-ai/flashinfer.git --recursive
cd flashinfer/python
python3.11 -m venv venv
source venv/bin/activate
pip install -e .

It returned this:

Looking in indexes: https://pypi.org/simple, https://pypi.ngc.nvidia.com
Obtaining file:///home/jovyan/flashinfer/python
  Installing build dependencies ... done
  Checking if build backend supports build_editable ... done
  Getting requirements to build editable ... error
  error: subprocess-exited-with-error

  × Getting requirements to build editable did not run successfully.
  │ exit code: 1
  ╰─> [23 lines of output]
      Traceback (most recent call last):
        File "/home/jovyan/flashinfer/python/venv/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module>
          main()
        File "/home/jovyan/flashinfer/python/venv/lib/python3.11/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/jovyan/flashinfer/python/venv/lib/python3.11/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 132, in get_requires_for_build_editable
          return hook(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-v7t0gp5t/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 458, in get_requires_for_build_editable
          return self.get_requires_for_build_wheel(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-v7t0gp5t/overlay/lib/python3.11/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-v7t0gp5t/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 297, in _get_build_requires
          self.run_setup()
        File "/tmp/pip-build-env-v7t0gp5t/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 497, in run_setup
          super().run_setup(setup_script=setup_script)
        File "/tmp/pip-build-env-v7t0gp5t/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 313, in run_setup
          exec(code, locals())
        File "<string>", line 28, 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 editable 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.

How do I solve something like this?

[yzh119]

Hi @Brennanzuz , you have to install torch first if you want to use FlashInfer in python.

[Brennanzuz]

Hmm, but I have it installed on my virtual environment already though with:

source venv/bin/activate
pip install torch
pip install -e .

And it still returned that. Sorry if this is a newbie question