It seems the file 'sparkle_dsa_pub.pem' is not necessary for running, but is there for legal requirements or something like that. You can find the file in the source control system at the address http://trac.transmissionbt.com/log/trun ... sa_pub.pem. As of right now the only file history on this file is that it was added in change set 6748, so it is being excluded from the tarball for some reason. As the change set was made for a reason I would advise downloading the file directly from source control and placing it in the 'macosx' subdirectory of your transmission source code.