anchor.diff:  
   cd ~/build/revdeplib/
   export R_LIBS=~/build/revdeplib/
  -R CMD INSTALL ~/data.table_1.9.7.tar.gz       # ** ensure latest version installed **
  +R CMD INSTALL ~/data.table_1.9.9.tar.gz       # ** ensure latest version installed **
   R
   
   # Follow: https://bioconductor.org/install/#troubleshoot-biocinstaller
  
positive.code: alias Rdevel='~/build/R-devel/bin/R --vanilla'
  Rdevel
  install.packages("bit64")  # important to run tests using integer64
  install.packages("knitr")  # to run examples in vignettes
  # Skip compatibility tests with other Suggests packages; unlikely UBSAN/ASAN problems there.
  q("no")
  Rdevel CMD INSTALL ~/data.table_1.9.7.tar.gz
  # Check UBSAN and ASAN flags appear in compiler output above. Rdevel was compiled with
  # them (above) so should be passed through to here
  Rdevel
  
negative.code: new = 0
  for (p in deps) {
     fn = paste0(p, "_", avail[p,"Version"], ".tar.gz")
     if (!file.exists(fn) || identical(tryCatch(packageVersion(p), error=function(e)FALSE), FALSE)) {
       system(paste0("rm -f ", p, "*.tar.gz"))  # Remove previous *.tar.gz.  -f to be silent if not there (i.e. first time seeing this package)
       system(paste0("rm -rf ", p, ".Rcheck"))  # Remove last check (of previous version)
       if (!length(grep("bioc",avail[p,"Repository"]))) {
  