i am trying to install go lang version 1.12.7 with
brew install go@1.12.7
but its saying formula is wrong. Any help would be appreciated.
There is no "simple way".
By default brew allows you set only last patch version for go1.12, because of formula file (right now it is 1.12.9).
But you can do it manually.
:~$ cd "$(brew --repo homebrew/core)"
:~$ git log --oneline Formula/go.rb # To see all old versions
:~$ git reset --hard go1.12.7
HEAD is now at fa46027fe go: update 1.12.7 bottle.
:~$ HOMEBREW_NO_AUTO_UPDATE=1 brew install go@1.12
==> Downloading https://homebrew.bintray.com/bottles/go-1.12.7.mojave.bottle.tar.gz