title: pyenv install: 3.x BUILD FAILED (Ubuntu 20.04 using python-build 20180424)
body: <p>Trying to install a new <code>Python</code> - version with <a href="https://github.com/pyenv/pyenv" rel="nofollow noreferrer">pyenv</a> on <a href="https://ubuntu.com/wsl" rel="nofollow noreferrer">Ubuntu 20.04 WSL for Windows 10</a> fails with the following output:</p>
  <pre><code>username@hd1pcms0347:~$ pyenv install 3.9.4
  Downloading Python-3.9.4.tar.xz...
  -&gt; https://www.python.org/ftp/python/3.9.4/Python-3.9.4.tar.xz
  Installing Python-3.9.4...
  python-build: use readline from homebrew
  
  BUILD FAILED (Ubuntu 20.04 using python-build 20180424)
  
  Inspect or clean up the working tree at /tmp/python-build.20210602162502.2268
  Results logged to /tmp/python-build.20210602162502.2268.log
  
  Last 10 log lines:
    File &quot;/tmp/python-build.20210602162502.2268/Python-3.9.4/Lib/ensurepip/__init__.py&quot;, line 210, in _main
      return _bootstrap(
    File &quot;/tmp/python-build.20210602162502.2268/Python-3.9.4/Lib/ensurepip/__init__.py&quot;, line 129, in _bootstrap
      return _run_pip(args + [p[0] for p in _PROJECTS], additional_paths)
    File &quot;/tmp/python-build.20210602162502.2268/Python-3.9.4/Lib/ensurepip/__init__.py&quot;, line 38, in _run_pip
      return subprocess.run([sys.executable, &quot;-c&quot;, code], check=True).returncode
    File &quot;/tmp/python-build.20210602162502.2268/Python-3.9.4/Lib/subprocess.py&quot;, line 528, in run
      raise CalledProcessError(retcode, process.args,
  subprocess.CalledProcessError: Command '['/tmp/python-build.20210602162502.2268/Python-3.9.4/python', '-c', '\nimport runpy\nimport sys\nsys.path = [\'/tmp/tmp7aa5f7ml/setuptools-49.2.1-py3-none-any.whl\', \'/tmp/tmp7aa5f7ml/pip-20.2.3-py2.py3-none-any.whl\'] + sys.path\nsys.argv[1:] = [\'install\', \'--no-cache-dir\', \'--no-index\', \'--find-links\', \'/tmp/tmp7aa5f7ml\', \'--root\', \'/\', \'--upgrade\', \'setuptools\', \'pip\']\nrunpy.run_module(&quot;pip&quot;, run_name=&quot;__main__&quot;, alter_sys=True)\n']' returned non-zero exit status 1.
  make: *** [Makefile:1255: install] Error 1
  </code></pre>
  <p>The <strong>entire log-file</strong> can be seen here under the following <em>GoogleDrive-Link</em> (as still only pictures can be shared in StackOverflow):</p>
  <p><a href="https://drive.google.com/file/d/1MKfRPy5-PWOGMW7ui-OaZiSmSopZV4hh/view?usp=sharing" rel="nofollow noreferrer">https://drive.google.com/file/d/1MKfRPy5-PWOGMW7ui-OaZiSmSopZV4hh/view?usp=sharing</a></p>