Updating brew install command to avoid pkg-config warning

[izumiberat]

I am using Mac OS Catalina 10.15.7.
To avoid getting the following warning :
configure: WARNING: pkg-config is missing. Some dependencies may not be detected correctly.
brew install pkg-config needs to be run.

Issue number: python/cpython#93658

[cpython-cla-bot]

All commit authors signed the Contributor License Agreement.

[erlend-aasland]

looks good to me

[ezio-melotti]

Which version of openssl gets installed if you don't specify the version number?
The error you mentioned in the issue says Python requires a OpenSSL 1.1.1 or newer and it seems odd to me that it would install an older version by default and require a pinned version to get a newer release. I wonder if that error is wrong 🤔

[izumiberat]

@ezio-melotti that is a very good point. I uninstalled openssl brew uninstall openssl, and verified that I would get the same message when compiling:

The necessary bits to build these optional modules were not found:
_hashlib _ssl

as well as

Python requires a OpenSSL 1.1.1 or newer

I then ran brew install openssl. This time it worked, it installs openSSL@3 the latest version. The message above didn’t show. I am sure though (I can still see it on the terminal), that installing openssl the first time, and following the instructions, lead to the message above. I believe that even though I uninstalled openssl, the uninstallation didn't remove all the files that were created when installing openssl1.1. I am therefore making this pull request purely about the warning issue and not the ssl module. I updated the related issue accordingly. If you think it is not out of the scope of the documentation, I will create a new issue and pull request, updating the documentation by adding a note saying that user might need to specify the latest version of openssl to be able to build the ssl module successfully. Let me know what you think.

[ezio-melotti]

Did you check which version of openssl gets installed by default (you can use openssl version to check)? FWIW on Linux I have OpenSSL 3.0.2 15 Mar 2022 (1.1.1 is from 2018-09-11 and 3.0.0 from 2021-09-07).
You could also try to run make clean or make distclean and then run ./configure and make again to start fresh and see if anything changes.

[ezio-melotti]

python/cpython#91357 (comment) might also be relevant -- maybe you were missing the libssl-dev package before? (cc @tiran)

[izumiberat]

@ezio-melotti It might be related but I have no quick way to check for sure now that I can't reproduce my issue in the first place! libssl-dev appears nowhere in my terminal. If I do a search on my laptop, I can find libssl.1.1.dylib and libssl.3.dylib but they were created a month ago, so not related. I am using brew and not pip so the part of the documentation that needs updating would be different in any case.

Once this PR is committed I will create a new issue and PR as I suggested. And yes, I did run make clean and ./configure before make for each of my attempts. Thanks for suggesting it.

[izumiberat]

@ezio-melotti regarding the openssl version, it returns LibreSSL 2.8.3. This is why I believe the documentation says to run ./configure --with-pydebug --with-openssl=$(brew --prefix openssl).
If I run brew info openssl , I get:

openssl@3: stable 3.0.3 (bottled) [keg-only]
Cryptography and SSL/TLS Toolkit
https://openssl.org/
/usr/local/Cellar/openssl@3/3.0.3 (6,441 files, 28.3MB)
Poured from bottle on 2022-06-10 at 10:37:27
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/openssl@3.rb
License: Apache-2.0
==> Dependencies
Required: ca-certificates ✔
==> Caveats
A CA file has been bootstrapped using certificates from the system
keychain. To add additional certificates, place .pem files in
/usr/local/etc/openssl@3/certs

and run
/usr/local/opt/openssl@3/bin/c_rehash

openssl@3 is keg-only, which means it was not symlinked into /usr/local,
because macOS provides LibreSSL.

If you need to have openssl@3 first in your PATH, run:
echo 'export PATH="/usr/local/opt/openssl@3/bin:$PATH"' >> ~/.zshrc

For compilers to find openssl@3 you may need to set:
export LDFLAGS="-L/usr/local/opt/openssl@3/lib"
export CPPFLAGS="-I/usr/local/opt/openssl@3/include"

For pkg-config to find openssl@3 you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/openssl@3/lib/pkgconfig"

==> Analytics
install: 137,635 (30 days), 449,281 (90 days), 995,856 (365 days)
install-on-request: 113,094 (30 days), 363,685 (90 days), 791,601 (365 days)
build-error: 4,447 (30 days)

[ezio-melotti]

I'm going to merge this since it fixes the pkg-config warning (see also related #750). We can continue the discussion about openssl in a different issue/PR.