Error: /usr/local/var/homebrew/linked/telnet is not inside a keg

[summerxue1992]

when i tried :

brew install telnet

I got this:
Warning: your HOMEBREW_PREFIX is set to /usr/local but HOMEBREW_CELLAR is set
to /usr/local/Homebrew/Cellar. Your current HOMEBREW_CELLAR location will stop
you being able to use all the binary packages (bottles) Homebrew provides. We
recommend you move your HOMEBREW_CELLAR to /usr/local/Cellar which will get you
access to all bottles."
Error: /usr/local/var/homebrew/linked/telnet is not inside a keg

[summerxue1992]

then i tried : export HOMEBREW_PREFIX=/usr/local/Homebrew

still got :

Warning: your HOMEBREW_PREFIX is set to /usr/local but HOMEBREW_CELLAR is set
to /usr/local/Homebrew/Cellar. Your current HOMEBREW_CELLAR location will stop
you being able to use all the binary packages (bottles) Homebrew provides. We
recommend you move your HOMEBREW_CELLAR to /usr/local/Cellar which will get you
access to all bottles."

[MikeMcQuaid]

Uninstall and reinstall Homebrew. Use brew bundle dump and brew bundle to export/import packages if needed.