I have installed Python 3.6.4 for macOS by downloading from the official site (www.python.org) and then tried installing 3.6.5 using pyenv.

Then the installation process hangs here:

https://user-images.githubusercontent.com/555156/38078784-57e44462-3378-11e8-8011-9579afc3c811.png

There is a 2-years old issue in pyenv (https://github.com/pyenv/pyenv/issues/512) but this may have to be fixed from here.

Sorry, we can't do much about pyenv issues, suggest you pursue with that project.  If pyenv uses the python.org installers, there is an installer option to avoid installing into /Applications.  If pyenv does its own Python framework build, it can install the framework and the Applications directory into any directory using the --enable-framework=/path/to/directory option of ./configure.

P.S. There *is* an old languishing issue, Issue11486, to add an option to configure to have framework builds not try to install into /Applications.  The patch there would need to be updated and turned into a PR for review.

I found that the reason was my Python 3.6.4 installed via the official-installer has the permission of "root:wheel" and pyenv is running in my plain user privilege. Using chown command to change the permissions to "joongi:admin" and retrying worked.

What I'm curious now is: why didn't "rm -r /Application/Python\ 3.6" command explicitly display the permission error and just the whole installation process hanged up?