Is:
sudo rake install -- --with-mysql-dir=/usr/local/mysql/
a valid terminal command? I try to run this but it doesn't seem to pass in the variable correctly..
However something like this works fine:
sudo gem install do_mysql -- --with-mysql-dir=/usr/local/mysql/
What are you trying to accomplish with that rake install command? rake is a scripting utility, pulling it's tasks from the next available "Rakefile", which is being watched for in the current and all preceding directories. You'd need an "install" task which processed the arguments (stored in ARGV-array in Ruby) if you wanted this to work