chruby reports exit status 0 under Bash, but still throws a Ruby exception when switching to mruby about chruby HOT 1 OPEN

local ruby_env="$(RUBYGEMS_GEMDEPS="" "$RUBY_ROOT/bin/ruby" - <<EOF
puts "export RUBY_ENGINE=#{Object.const_defined?(:RUBY_ENGINE) ? RUBY_ENGINE : 'ruby'};"
puts "export RUBY_VERSION=#{RUBY_VERSION};"
begin; require 'rubygems'; puts "export GEM_ROOT=#{Gem.default_dir.inspect};"; rescue LoadError; end
EOF)"

if (( $? != 0 )); then
  echo "chruby: failed to execute $1/bin/ruby command" >&2
  return -1
fi