rb-memcacheのインストールでこける

% sudo port install rb-memcache

--->  Staging rb-memcache into destrootError:
 Target com.apple.destroot returned: shell command
 "cd "/opt/local/var/db/dports/build/_opt_local_var_db_dpor
ts_sources_rsync.rsync.darwinports.org_dpupdate_dports_ruby
_rb-memcache/work/Ruby-MemCache-0.0.2" && DESTROOT=/opt/loc
al/var/db/dports/build/_opt_local_var_db_dports_sources_rsy
nc.rsync.darwinports.org_dpupdate_dports_ruby_rb-memcache/w
ork/destroot /opt/local/bin/ruby -rvendor-specific -rdestro
ot install.rb" returned error 1Command output: Error: Statu
s 1 encountered during processing.

gemsにいくつかあるっぽいので、そっちを試そう。