this works for me:

Step 1 (install HomeBrew)

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh )

echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> /Users/”YOUR USER FORLDER”/.zprofile

eval "$(/opt/homebrew/bin/brew shellenv)"

brew install cocoapods

Step 1:

Install brew

1. curl -fsSL -o install.sh https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh
2. /bin/bash install.sh
Step 2:
brew install chruby ruby-install
Step 3:
brew install cocoapods
Step 4: (Check your cocoapods version):
brew upgrade cocoapods
Need Xcode Command Line Tools, if not installed then run this command: sudo xcode-select --install
It's works for me
          
I was getting this exact error mentioned.
In my case, the MacOs update for BigSur + Monterey update, solved the problem like a charm.
After Monterey got installed I could pod install normally with no more errors.
          
What I did was run the following and it seemed to work
gem install cocoapods --user-install
I guess from there you need to update your path to point to the user directory.
        
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