Failed to install Homebrew Portable Ruby (and your system version is too old)

Solution 1:

I had the same question, and the solution is simple: remove the portable-ruby-2.6.3.mavericks.bottle.tar.gz you downloaded before.

rm /.../Library/Caches/Homebrew/portable-ruby-2.6.3.mavericks.bottle.tar.gz

Solution 2:

Try running brew update-reset in your terminal and then run brew upgrade in the same terminal.

Solution 3:

"Homebrew install fails with Error: Failed to install Homebrew Portable Ruby" helped me tremendously.

It would fail to install, because our company firewall was blocking certain downloads, like bottle, during the Homebrew update/install, but it was difficult to determine this because I would get the error above.

After removing the file, try

brew upgrade
brew update

on your personal Wifi or your phone's hotspot.

Solution 4:

I fixed it.

First, I deleted the brew file that stores in the Library folder when using macOS.

The failure before was due to the connection. When I make sure the connection worked, it worked.