I can’t do anything about it if you don’t have write permissions to your own files. Let me be more clear about how to check:
Go to the tools/build directory (???/rosetta_source/tools/build)
Type in “ls -l”, and let me know what it returns. The pattern on the left should start “-rw-r–r–“, which means you have permissions to read and write the file. If it doesn’t start that way, then you need to start from scratch by untar-ing the Rosetta tarball someplace where you will have write permissions.