I run the following code, which show that there are no openssl repo find in brew.
My Mac is macOS Big Sur 11.3.1
% brew install openssl
Updating Homebrew...
fatal: Could not resolve HEAD to a revision
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/cask).
==> Updated Casks
Updated 1 cask.
Warning: No available formula or cask with the name "openssl".
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching for a previously deleted formula (in the last month)...
Error: No previously deleted formula found.
==> Searching taps on GitHub...
This formula was found in a tap:
homebrew/portable-ruby/portable-openssl
To install it, run:
brew install homebrew/portable-ruby/portable-openssl
UPDATE
Seems that my brew can't install ccache either like the following. It is more of a brew issue?
brew install ccache
The following commands help
cd /usr/local/Homebrew/Library/Taps/homebrew/
rm -rf homebrew-core
git clone https://github.com/Homebrew/homebrew-core.git