Debian drops the SPARC architecture
The Debian release team has announced that the SPARC port can no longer be
found in the testing distribution. "The main reasons were
lack of porter commitments, problems with the toolchain and continued
stability issues with our machines.

The fate of SPARC in unstable has not been decided yet. It might get
removed unless people commit to working on it." See this bug
entry for discussion on the future of this port.