Python3, gcc and clang on MacOS

Question

I am trying to make a Python script on my Mac (MacOS 10.14.6 Mojave) and I am getting trouble with installing a module (watchdog). I have the built-in Python 2 and I installed Python 3 with Homebrew.

If a type in the terminal python, I get:

Python 2.7.16 (default, Oct 16 2019, 00:34:56) 
[GCC 4.2.1 Compatible Apple LLVM 10.0.1 (clang-1001.0.37.14)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

So Python 2 correctly uses GCC (the one provided by Apple? I am not sure) instead of Clang. Now, if I do python -m pip install watchdog it just works. But I want to install the module on Python 3, that for some reason uses Clang instead of GCC. In fact, if I type `python3', I get:

Python 3.8.0 (v3.8.0:fa919fdf25, Oct 14 2019, 10:23:27) 
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

I assume that as a consequence python3 -m pip install watchdog gives a compile error because Python 3 is not using GCC. The error message is very long and can be found here: https://pastebin.com/DEAKANQ9

In my $PATH I have /usr/local/bin (where gcc is installed) before /usr/bin, i.e.

echo $PATH
/Library/Frameworks/Python.framework/Versions/3.8/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin:/opt/X11/bin

I would say everything is set up correctly, but apparently that is not the case. How can I make Python 3 use GCC instead of Clang?

Answer 1

I have fixed the issue. First, I have removed Python 3.8 which was installed using the pkg installer (by accident actually). Then, I have created an alias for Python 3 in the .bash_profile. Another mistake was that I created the file ~/.bashrc (as in Ubuntu) instead of editing the file ~/.bash_profile to modify the $PATH.

# ~/.bash_profile
#
# Python alias
alias python=/usr/local/bin/python3
# Setting PATH for Python 3.7.5 (Homebrew)
PATH="/usr/local/bin:${PATH}"
export PATH

# Set module path
PYTHONPATH=$PYTHONPATH:/usr/local/lib/python3.7/site-packages

# Set PATH priority to Homebrew installation folder
export PATH=/usr/local/bin:/usr/local/sbin:$PATH

With this settings, I was able to install the module and make it work in my script!