[python] What is the meaning of "Failed building wheel for X" in pip install?

This is a truly popular question here at SO, but none of the many answers I have looked at, clearly explain what this error really mean, and why it occurs.

One source of confusion, is that when (for example) you do pip install pycparser, you first get the error:

Failed building wheel for pycparser

which is then followed by the message that the package was:

Successfully installed pycparser-2.19.

# pip3 install pycparser

Collecting pycparser
  Using cached https://files.pythonhosted.org/packages/68/9e/49196946aee219aead1290e00d1e7fdeab8567783e83e1b9ab5585e6206a/pycparser-2.19.tar.gz
Building wheels for collected packages: pycparser
  Running setup.py bdist_wheel for pycparser ... error
  Complete output from command /usr/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-install-g_v28hpp/pycparser/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /tmp/pip-wheel-__w_f6p0 --python-tag cp36:
  Traceback (most recent call last):
    File "<string>", line 1, in <module>
    ...
    File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 2349, in resolve
      module = __import__(self.module_name, fromlist=['__name__'], level=0)
  ModuleNotFoundError: No module named 'wheel.bdist_wheel'

  ----------------------------------------
  Failed building wheel for pycparser
  Running setup.py clean for pycparser
Failed to build pycparser
Installing collected packages: pycparser
  Running setup.py install for pycparser ... done
Successfully installed pycparser-2.19

What is going on here?

(I would like to understand how something can fail but still get installed and whether you can trust this package functioning correctly?)

So far the best partial explanation I have found is this.

I got the same message when I tried to install pip install django-imagekit. So I ran pip install wheel (I had python 2.7) and then I reran pip install django-imagekit and it worked. Thanks

It might be helpful to address this question from a package deployment perspective.

There are many tutorials out there that explain how to publish a package to PyPi. Below are a couple I have used;

medium
real python

My experience is that most of these tutorials only have you use the .tar of the source, not a wheel. Thus, when installing packages created using these tutorials, I've received the "Failed to build wheel" error.

I later found the link on PyPi to the Python Software Foundation's docs PSF Docs. I discovered that their setup and build process is slightly different, and does indeed included building a wheel file.

After using the officially documented method, I no longer received the error when installing my packages.

So, the error might simply be a matter of how the developer packaged and deployed the project. None of us were born knowing how to use PyPi, and if they happened upon the wrong tutorial -- well, you can fill in the blanks.

I'm sure that is not the only reason for the error, but I'm willing to bet that is a major reason for it.

I would like to add that if you only have Python3 on your system then you need to start using pip3 instead of pip.

You can install pip3 using the following command;

sudo apt install python3-pip -y

After this you can try to install the package you need with;

sudo pip3 install <package>

On Ubuntu 18.04, I ran into this issue because the apt package for wheel does not include the wheel command. I think pip tries to import the wheel python package, and if that succeeds assumes that the wheel command is also available. Ubuntu breaks that assumption.

The apt python3 code package is named python3-wheel. This is installed automatically because python3-pip recommends it.

The apt python3 wheel command package is named python-wheel-common. Installing this too fixes the "failed building wheel" errors for me.

In my case, update the pip versión after create the venv, this update pip from 9.0.1 to 20.3.1

python3 -m venv env/python
source env/python/bin/activate
pip3 install pip --upgrade

But, the message was...

Using legacy 'setup.py install' for django-avatar, since package 'wheel' is not installed.

Then, I install wheel package after update pip

python3 -m venv env/python
source env/python/bin/activate
pip3 install --upgrade pip
pip3 install wheel

And the message was...

Building wheel for django-avatar (setup.py): started
default:   Building wheel for django-avatar (setup.py): finished with status 'done'

(pip maintainer here!)

If the package is not a wheel, pip tries to build a wheel for it (via setup.py bdist_wheel). If that fails for any reason, you get the "Failed building wheel for pycparser" message and pip falls back to installing directly (via setup.py install).

Once we have a wheel, pip can install the wheel by unpacking it correctly. pip tries to install packages via wheels as often as it can. This is because of various advantages of using wheels (like faster installs, cache-able, not executing code again etc).

Your error message here is due to the wheel package being missing, which contains the logic required to build the wheels in setup.py bdist_wheel. (pip install wheel can fix that.)

The above is the legacy behavior that is currently the default; we'll switch to PEP 517 by default, sometime in the future, moving us to a standards-based process for this. We also have isolated builds for that so, you'd have wheel installed in those environments by default. :)

• PEP 517: A build-system independent format for source trees
• A blog post on "PEP 517 and 518 in Plain English"

This may Help you ! ....

Uninstalling pycparser:

pip uninstall pycparser

Reinstall pycparser:

pip install pycparser

I got same error while installing termcolor and I fixed it by reinstalling it .

Yesterday, I got the same error: Failed building wheel for hddfancontrol when I ran pip3 install hddfancontrol. The result was Failed to build hddfancontrol. The cause was error: invalid command 'bdist_wheel' and Running setup.py bdist_wheel for hddfancontrol ... error. The error was fixed by running the following:

 pip3 install wheel

(From here.)

Alternatively, the "wheel" can be downloaded directly from here. When downloaded, it can be installed by running the following:

pip3 install "/the/file_path/to/wheel-0.32.3-py2.py3-none-any.whl"

I had the same problem while installing Brotli

ERROR

Failed building wheel for Brotli

I solved it by downloading the .whl file from here and installing it using the below command

C:\Users\{user_name}\Downloads>pip install Brotli-1.0.9-cp39-cp39-win_amd64.whl

Try this:

sudo apt-get install libpcap-dev libpq-dev

It has worked for me when I have installed these two.

See the link here for more information

Error :

System : aws ec2 instance (t2 small)

issue : while installing opencv python via

pip3 install opencv-python

  Problem with the CMake installation, aborting build. CMake executable is cmake
  
  ----------------------------------------
  Failed building wheel for opencv-python
  Running setup.py clean for opencv-python

What worked for me

pip3 install --upgrade pip setuptools wheel

After this you still might received fallowing error error

    from .cv2 import *
ImportError: libGL.so.1: cannot open shared object file: No such file or directory

Installing libgl solved the error for me.

sudo apt update
sudo apt install libgl1-mesa-glx

Hope this helps