• using R Under development (unstable) (2012-05-19 r59366)
• using platform: x86_64-unknown-linux-gnu (64-bit)
• using session charset: UTF-8
• checking for file ‘DeducerExtras/DESCRIPTION’ ... OK
• checking extension type ... Package
• this is package ‘DeducerExtras’ version ‘1.5’
• checking package namespace information ... OK
• checking package dependencies ... ERROR
  Package required but not available: ‘Deducer’
  
  See the information on DESCRIPTION files in the chapter ‘Creating R
  packages’ of the ‘Writing R Extensions’ manual.