anchor.diff:  
   RUN rm \
       modelr_0.1.2.tar.gz \
  +    clisymbols_1.2.0.tar.gz \
       desc_1.2.0.tar.gz \
       praise_1.0.0.tar.gz \
       rex_1.1.2.tar.gz \
  
positive.code:     desc_1.2.0.tar.gz \
      pkgbuild_1.0.0.tar.gz \
      pkgload_1.0.0.tar.gz \
      rcmdcheck_1.2.1.tar.gz \
      sessioninfo_1.0.0.tar.gz \
      usethis_1.4.0.tar.gz \
  
negative.code:     https://mirrors.nics.utk.edu/cran/src/contrib/stringdist_0.9.5.1.tar.gz \
      https://mirrors.nics.utk.edu/cran/src/contrib/praise_1.0.0.tar.gz \
      https://mirrors.nics.utk.edu/cran/src/contrib/desc_1.2.0.tar.gz \
      https://mirrors.nics.utk.edu/cran/src/contrib/clisymbols_1.2.0.tar.gz \
      https://mirrors.nics.utk.edu/cran/src/contrib/bench_1.0.1.tar.gz 
  
  RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
  