Install VirtualBox on MacOS using HomeBrew

I’m fairly new on using MacOS. I’ve been struggling finding shortcuts and keys that I was very comfortable with in Windows. I friend of mine helped me with tips and also mentioned to install HomeBrew in order to install VirtualBox. Here’s a short post on how to do it.
First you need to install Xcode. Xcode is a MacOS development framework application.
$:~ user$ xcode-select –install
xcode-select: note: install requested for command line developer tools
Then, you need to install HomeBrew. This version of HomeBrew doesn’t require to install Cask separately.
$:~ user$ ruby -e “$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)”
==> This script will install:
/usr/local/bin/brew
/usr/local/share/doc/homebrew
/usr/local/share/man/man1/brew.1
/usr/local/share/zsh/site-functions/_brew
/usr/local/etc/bash_completion.d/brew
/usr/local/Homebrew
==> Homebrew is run entirely by unpaid volunteers. Please consider donating:
  https://github.com/Homebrew/brew#donations
==> Tapping homebrew/core
Cloning into ‘/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core’…
remote: Enumerating objects: 4894, done.
remote: Counting objects: 100% (4894/4894), done.
remote: Compressing objects: 100% (4697/4697), done.
remote: Total 4894 (delta 52), reused 324 (delta 6), pack-reused 0
Receiving objects: 100% (4894/4894), 4.00 MiB | 372.00 KiB/s, done.
Resolving deltas: 100% (52/52), done.
Tapped 2 commands and 4680 formulae (4,936 files, 12.4MB).
Already up-to-date.
==> Installation successful!
==> Homebrew has enabled anonymous aggregate formulae and cask analytics.
Read the analytics documentation (and how to opt-out) here:
  https://docs.brew.sh/Analytics
==> Homebrew is run entirely by unpaid volunteers. Please consider donating:
  https://github.com/Homebrew/brew#donations
==> Next steps:
– Run `brew help` to get started
– Further documentation:
As I previously mentioned, Cask is already included in the HomeBrew installation.
Now, lest try to use HomeBrew to search for the VirtualBox package.
$:~ user$ brew search virtualbox
==> Casks
homebrew/cask-versions/virtualbox-beta
homebrew/cask-versions/virtualbox-extension-pack-beta
homebrew/cask/virtualbox
homebrew/cask/virtualbox-extension-pack
$:~ user$ brew cask info virtualbox
==> Tapping homebrew/cask
Cloning into ‘/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask’…
remote: Enumerating objects: 4195, done.
remote: Counting objects: 100% (4195/4195), done.
remote: Compressing objects: 100% (4185/4185), done.
remote: Total 4195 (delta 26), reused 915 (delta 7), pack-reused 0
Receiving objects: 100% (4195/4195), 1.33 MiB | 241.00 KiB/s, done.
Resolving deltas: 100% (26/26), done.
Tapped 1 command and 4096 casks (4,205 files, 4.2MB).
virtualbox: 6.0.0,127566
https://www.virtualbox.org/
Not installed
From: https://github.com/Homebrew/homebrew-cask/blob/master/Casks/virtualbox.rb
==> Name
Oracle VirtualBox
==> Artifacts
VirtualBox.pkg (Pkg)
==> Caveats
To install and/or use virtualbox you may need to enable their kernel extension in
  System Preferences Security & Privacy General
For more information refer to vendor documentation or the Apple Technical Note:
  https://developer.apple.com/library/content/technotes/tn2459/_index.html
Now is time to install VirtualBox.
$:~ user$ brew cask install virtualbox
==> Caveats
To install and/or use virtualbox you may need to enable their kernel extension in
  System Preferences Security & Privacy General
For more information refer to vendor documentation or the Apple Technical Note:
  https://developer.apple.com/library/content/technotes/tn2459/_index.html
==> Satisfying dependencies
==> Downloading https://download.virtualbox.org/virtualbox/6.0.0/VirtualBox-6.0.
######################################################################## 100.0%
==> Verifying SHA-256 checksum for Cask ‘virtualbox’.
==> Installing Cask virtualbox
==> Running installer for virtualbox; your password may be necessary.
==> Package installers may write to any location; options such as –appdir are i
Password:
installer: Package name is Oracle VM VirtualBox
installer: Installing at base path /
installer: The install failed (The Installer encountered an error that caused the installation to fail. Contact the software manufacturer for assistance.)
==> Purging files for version 6.0.0,127566 of Cask virtualbox
Error: Failure while executing; `/usr/bin/sudo -E — env LOGNAME=user USER=user USERNAME=user /usr/sbin/installer -pkg /usr/local/Caskroom/virtualbox/6.0.0,127566/VirtualBox.pkg -target /` exited with 1. Here’s the output:
installer: Package name is Oracle VM VirtualBox
installer: Installing at base path /
installer: The install failed (The Installer encountered an error that caused the installation to fail. Contact the software manufacturer for assistance.)
Follow the instructions here:
  https://github.com/Homebrew/homebrew-cask#reporting-bugs
/usr/local/Homebrew/Library/Homebrew/system_command.rb:107:in `assert_success’
/usr/local/Homebrew/Library/Homebrew/system_command.rb:50:in `run!’
/usr/local/Homebrew/Library/Homebrew/system_command.rb:27:in `run’
/usr/local/Homebrew/Library/Homebrew/system_command.rb:31:in `run!’
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:59:in `block in run_installer’
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:65:in `with_choices_file’
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:52:in `run_installer’
/usr/local/Homebrew/Library/Homebrew/cask/artifact/pkg.rb:32:in `install_phase’
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:209:in `block in install_artifacts’
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/set.rb:674:in `each’
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/set.rb:674:in `each’
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:200:in `install_artifacts’
/usr/local/Homebrew/Library/Homebrew/cask/installer.rb:95:in `install’
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:21:in `block in run’
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:14:in `each’
/usr/local/Homebrew/Library/Homebrew/cask/cmd/install.rb:14:in `run’
/usr/local/Homebrew/Library/Homebrew/cask/cmd/abstract_command.rb:34:in `run’
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:89:in `run_command’
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:155:in `run’
/usr/local/Homebrew/Library/Homebrew/cask/cmd.rb:120:in `run’
/usr/local/Homebrew/Library/Homebrew/cmd/cask.rb:7:in `cask’
/usr/local/Homebrew/Library/Homebrew/brew.rb:88:in `’
$:~ user$
As you can see, my installation failed. This is due to a new MacOS Sierra feature that prevents to load external libraries. I had to follow the instructions in below note:
Now that I have approved the extension let’s execute the install again.
$:~ user$ brew cask install –force virtualbox
==> Caveats
To install and/or use virtualbox you may need to enable their kernel extension in
  System Preferences Security & Privacy General
For more information refer to vendor documentation or the Apple Technical Note:
  https://developer.apple.com/library/content/technotes/tn2459/_index.html
==> Satisfying dependencies
==> Downloading https://download.virtualbox.org/virtualbox/6.0.0/VirtualBox-6.0.
Already downloaded: /Users/user/Library/Caches/Homebrew/downloads/c68cfddc9133da5c221557cd77b23f34e0b513dc380e6b010dc36b3d0eb2df45–VirtualBox-6.0.0-127566-OSX.dmg
==> Verifying SHA-256 checksum for Cask ‘virtualbox’.
==> Installing Cask virtualbox
==> Running installer for virtualbox; your password may be necessary.
==> Package installers may write to any location; options such as –appdir are i
installer: Package name is Oracle VM VirtualBox
installer: Installing at base path /
installer: The install was successful.
virtualbox was successfully installed!
Now, just use spotlight search to find the VirtualBox application.
Hope this helps.
Alfredo