Python 3.8 was installed from source on Ubuntu 19.04 desktop and a virtual environment was created with python3.8 -m venv venvrh. When attempting to use pip to install a package, the following error was encountered:

(venvrh) jgossage@jgossage-XPS-8700:~/Projects/Maintenance$ pip install sphinx
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting sphinx
  WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/sphinx/
  WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/sphinx/
  WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/sphinx/
  WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/sphinx/
  WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/sphinx/
  Could not fetch URL https://pypi.org/simple/sphinx/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/sphinx/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping
  ERROR: Could not find a version that satisfies the requirement sphinx (from versions: none)
ERROR: No matching distribution found for sphinx
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Could not fetch URL https://pypi.org/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/pip/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping

As the error says:

> Can't connect to HTTPS URL because the SSL module is not available.

Since you built it from source, you should check your build logs, the _ssl module likely failed to build. You're most probably missing the openssl dependency.

I guess it's due to the binary not being built with ssl module. During build did you get a message like below ? 


Could not build the ssl module!
Python requires an OpenSSL 1.0.2 or 1.1 compatible libssl with X509_VERIFY_PARAM_set1_host().
LibreSSL 2.6.4 and earlier do not provide the necessary APIs, https://github.com/libressl-portable/portable/issues/381

In the REPL you can verify it by trying to import ssl module that would fail if python was not built with ssl

./python.exe
Python 3.9.0a0 (heads/pr_16148:1a801bd50d, Sep 16 2019, 22:15:26)
[Clang 7.0.2 (clang-700.1.81)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import ssl
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/ssl.py", line 98, in <module>
    import _ssl             # if we can't import it, let the error propagate
ModuleNotFoundError: No module named '_ssl'

I close this issue, it's not related to the packaging of Python, but just to your compilation.

As explained by Ammar Askar, when you compile Python, you have to be sure that you have the openssl-dev package installed on your system

You can read this page: https://cpython-core-tutorial.readthedocs.io/en/latest/build_cpython_linux.html