Actually install the correct version of ruby to install cocoapods

- If we already have the desired version, we are good
- If we don't, but we have brew, we install the desired version
- If we don't have brew, but we have a sufficiently recent OSX, we are good
- If we don't have brew and we don't have a sufficiently recent OSX, we warn that there might be problems

README.md

@@ -120,6 +120,10 @@ Pre-requisites
     ```
 
     </details>
+- if you are not on the most recent version of OSX, `homebrew`
+    - this allows us to install the current version of cocoapods without
+      running into ruby incompatibilities - e.g.
+      https://github.com/CocoaPods/CocoaPods/issues/11763
 
 Important
 ---

setup/export_shared_dep_versions.sh

@@ -1,9 +1,14 @@
 export NVM_VERSION=0.39.0
 export NODE_VERSION=14.18.1
 export NPM_VERSION=6.14.15
-export RUBY_VERSION=2.6.0
+# make sure that this is a stable version from
+# so that https://github.com/postmodern/ruby-versions
+# ideally, this would be the same version as the CI
+# Looks like brew supports only major and minor, not patch version
+export RUBY_VERSION=2.7
 export COCOAPODS_VERSION=1.11.2
 export GRADLE_VERSION=7.1.1
+export OSX_EXP_VERSION=12
 
 export NVM_DIR="$HOME/.nvm"
-export RUBY_PATH=$HOME/.gem/ruby/$RUBY_VERSION/bin
+export RUBY_PATH=$HOME/.gem/ruby/$RUBY_VERSION.0/bin

setup/setup_ios_native.sh

@@ -4,26 +4,34 @@ set -e
 # Setup the development environment
 source setup/setup_shared.sh
 
-# Importing rvm keys
-curl -sSL https://rvm.io/mpapis.asc | gpg2 --import -
-curl -sSL https://rvm.io/pkuczynski.asc | gpg2 --import -
-
-# Download and install rvm
-echo "Installing stable rvm"
-curl -sSL https://get.rvm.io | bash -s stable
-
-# Enable rvm
-source /Users/kshankar/.rvm/scripts/rvm
-
-# Download and install ruby
-echo "Installing ruby $RUBY_VERSION"
-rvm install ruby-$RUBY_VERSION
-
-echo "Switching to ruby version $RUBY_VERSION"
-rvm use $RUBY_VERSION
-
+OSX_MAJOR_VERSION=`sw_vers | grep ProductVersion | cut -d ':' -f 2 | cut -d '.' -f 1`
+echo "Found OSX major version" $OSX_MAJOR_VERSION
+
+CURR_RUBY_VERSION=`ruby --version | cut -d ' ' -f 2 | cut -d '.' -f 1-2`
+echo "Found ruby version "$CURR_RUBY_VERSION
+
+if [ $CURR_RUBY_VERSION == $RUBY_VERSION ]; then
+    echo "Found ruby version "$CURR_RUBY_VERSION" expected "$RUBY_VERSION" no need to upgrade"
+else
+    if [ -x /usr/local/bin/brew ]; then
+        echo "Found brew installation with version" `/usr/local/bin/brew --version`
+        echo "Installing ruby version to brew" $RUBY_VERSION
+        brew install ruby@$RUBY_VERSION
+    else
+        if [ $OSX_MAJOR_VERSION -ge $OSX_EXP_VERSION ]; then
+            echo "No brew installation found, but OSX major version "$OSX_MAJOR_VERSION" and expected version "$OSX_EXP_VERSION" so CocoaPods should work"
+        else
+            echo "No brew installation found, but OSX major version "$OSX_MAJOR_VERSION" != expected version "$OSX_EXP_VERSION" CocoaPods install will likely fail"
+            echo "Found ruby version "`ruby --version`
+            exit 1
+        fi
+    fi
+fi
+
+echo "Adding $RUBY_PATH to the path before the install"
 export PATH=$RUBY_PATH:$PATH
+
 echo "Installing cocoapods"
-gem install --no-document --user-install cocoapods -v $COCOAPODS_VERSION
+/usr/local/opt/ruby@$RUBY_VERSION/bin/gem install --no-document --user-install cocoapods -v $COCOAPODS_VERSION
 
 source setup/setup_shared_native.sh