Missing dependency PyYAML with Nikola-8.0.1 refresh installtion

[monkeyxite]

Environment (if reporting a bug)

Python Version:
3.7.0
Nikola Version:
Nikola-8.0.1
Operating System:
Mac

Description:

Refresh installation after pip, occur the dependency missing issue with PyYAML when creating new post. error message like this.

Creating New Post

Title: Test Nicula
Scanning posts..[2018-10-13T15:46:03Z] ERROR: Nikola: In order to use YAML metadata, you must install the "PyYAML" Python package.
[2018-10-13T15:46:03Z] ERROR: Nikola: Exiting due to missing dependencies.

After pip install PyYaml, all settled.

Suppose requirements.txt should be updated.

[Kwpolska]

Not really. requirements.txt contains the basic, mandatory requirements. Your site uses the YAML metadata format, as configured, so you also have to install PyYAML on your own. (Note this message was generated by Nikola on purpose.)

You can use pip install 'Nikola[extras]' to get Nikola with all the extra requirements.