Were you root or su when you started the "make install clean"? You need to be. It looks like you were prompted for the su password for the single step, returned to user (like it says), and then were unable to write into /usr/ports. That is how it should be.
Also, it shows that you have a configuration file for flash already. What does
"ls /var/db/pkg | grep flash" (without the quotes) return?
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