anchor.diff:  LANGUAGE=de R
   require(data.table)
   test.data.table()
  +q("no")
   
   R
   remove.packages("xml2")    # we checked the URLs; don't need to do it again (many minutes)
   require(data.table)
   test.data.table()
  -test.data.table(with.other.packages=TRUE)
  +test.data.table(script="other.Rraw")
   test.data.table(verbose=TRUE)   # since main.R no longer tests verbose mode
   gctorture2(step=50)
   system.time(test.data.table())  # apx 4hrs
  
positive.code: cd R-devel-strict    # important to change directory name before building not after because the path is baked into the build, iiuc
  # Following R-exts#4.3.3
  
  ./configure --without-recommended-packages --disable-byte-compiled-packages --disable-openmp --enable-strict-barrier CC="gcc -fsanitize=undefined,address -fno-sanitize=float-divide-by-zero -fno-omit-frame-pointer" CFLAGS="-O0 -g -Wall -pedantic" LIBS="-lpthread"
  # For ubsan, disabled openmp otherwise gcc fails in R's distance.c:256 error: ‘*.Lubsan_data0’ not specified in enclosing parallel
  # UBSAN gives direct line number under gcc but not clang it seems. clang-5.0 has been helpful too, though.
  # If use later gcc-8, add F77=gfortran-8
  
negative.code: grep --exclude="./src/openmp-utils.c" omp_get_max_threads ./src/*
  
  # Ensure all #pragama omp parallel directives include a num_threads() clause
  grep "pragma omp parallel" ./src/*.c | grep -v getDTthreads
  
  # Ensure all .Call's first argument are unquoted.
  grep "[.]Call(\"" ./R/*.R
  
  # Ensure no Rprintf in init.c
  