How to fix: The volume can't be ejected because it's currently in use

After working with an external hard drive (further simply - disk) I want to cleanly unmount it. But to my surprise when pressing the ‘eject’ button Finder warns me with the following error messages:

The volume can't be ejected because it's currently in use.

How to fix: fatal: Authentication failed for https://github.com/

After enabling a two-factor authentication in my GitHub account, when I run the Git git push command it throws the following error message:

$ git push
Username for 'https://github.com': Username
Password for 'https://Username@github.com':
remote: Invalid username or password.
fatal: Authentication failed for 'https://github.com/username/repository.git/'

How to fix: MediaKit reports not enough space on device for requested operation

Today I bought a brand new external hard drive WD Elements Portable 1Tb. A Western Digital company says that it can be used on both Windows and macOS. But most WD drives come formatted in the NTFS file system format for OS Windows, while for macOS we needed the HFS+ format or the Apple’s brand new APFS (Apple File System) format.

How to fix: bundler: command not found: jekyll

We can set up a local version of our Jekyll GitHub Pages website to preview our website before making the changes public. But after upgrading MacOS to version “High Sierra” on my MacBook, when I run the jekyll bundle exec jekyll serve command it throws the following error message:

$ bundle exec jekyll serve
bundler: command not found: jekyll
Install missing gem executables with `bundle install`

How to fix: Your user account isn't allowed to install to the system RubyGems

This happened to me after upgrading MacOS to version “High Sierra” on my MacBook. I cloned my application repository and went to execute a bundle install command, but it throws the following error message: