Why am I getting error saying "Could not find a version that satisfies the requirement Cython"

Question

What am I trying to achieve?

I am trying to finish tuotorial on making android app with kivy with buildozer running in Ubuntu VirtualBox inside windows 10 (isntructions from this tutorial: https://www.youtube.com/watch?v=EupAeyL8zAo) and run the app on my mobile device.

Where am I having problems?

For five times I've tried this I have had this error after running command buildozer android debug deploy run (from inside the project's folder):

What have I tried to fix this?

• I installed cython to both my windows 10 (with pip install Cython and pip3 install Cython) and Ubunu inside VirtualBox. In every instance I got Requirement already satisfied....
• I started new VirtualBox enviroment after installing Cython to windows 10.
• I tried following these instructons/commands: https://stackoverflow.com/a/68452164/14694631

PS

In many posts I have seen people asking for full logs. Still after reading many issues on this subject I am still clueless on what the full log actually means. If error message provided is not the right part I can try to get the full log also if I can. Also I am new to Kivy, buildozer and VirtualBox and I've never used ubuntu for dev stuff before.

Answer 1

I faced the same prob when I was trying to install mobsf. Here is how I managed to fix it:

First, locate oscrypto/version.py and check what's the value of __version__.

Then, just hardcode it inside oscrypto/_openssl/_libcrypto_cffi.py, find where the variable called version_string is being set, comment that link and just set version_string = "THE VALUE YOU FOUND INSIDE version.py"

Please note that this may not be the best solution, but it worked for me after trying all the above answers.

Answer 2

I found fix in the comments of the tutorial.

1. sudo apt install libssl-dev
2. rm -rf .buildozer
3. Deploy app again

Here is the whole comment by tutorial maker Erik Sanberg:

Try sudo apt install libssl-dev and then rm -rf .buildozer in the directory that has your buildozer.spec file. Then you can try deploying it again. It's a bug recently introduced that will be patched up soon I believe.

Source: https://www.youtube.com/watch?v=EupAeyL8zAo

Answer 3

I've seen a similar error before and seems that when installing python, some essential modules, ssl, weren't and are missing.

The Problem

pip seems to fail when trying to download Cython during the build, as it needs the ssl module in python which isn't available

The Solution

re-installing Python3 as it seems an essential library (ssl) wasn't installed.

You could use this question for help in fixing the ssl error in pip, and you should then retry the build

To re-install python, it says to:

1. Run sudo apt-get install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev for dependancies

2. Download and unzip "Python-3.x.x.tar.xz" (your choice of version) from https://www.python.org/ftp/python/ into your home directory.

3. Open terminal in that directory and run: ./configure

4. Build and install: make && sudo make install

After re-installing python, check if pip works by running pip install --upgrade pip

If you need more clarifications, just comment.