anchor.diff:  
   cd ..
   R
  -cc(clean=TRUE)  # to compile with -pedandic. Also use very latest gcc (currently gcc-7) as CRAN does
  +cc(clean=TRUE)  # to compile with -pedandic -Wall -flto. Also uses very latest gcc (currently gcc-7) as CRAN does
   saf = options()$stringsAsFactors
   options(stringsAsFactors=!saf)    # check tests (that might be run by user) are insensitive to option, #2718
   test.data.table()
  
positive.code: #############################################################################
  There are some things to overcome to achieve compile without USE_RINTERNALS, though.
  
  
  ########################################################################
  #  Single precision e.g. CRAN's Solaris-Sparc when it was alive on CRAN.
  #  Not Solaris-x86 which is still on CRAN and easier.
  ########################################################################
  #
  # Adding --disable-long-double (see R-exts) in the same configure as ASAN/UBSAN fails.  Hence separately.
  ## cd ~/build
  ## rm -rf R-devel    # 'make clean' isn't enough: results in link error, oddly.
  ## tar xvf R-devel.tar.gz
  ## cd R-devel
  ## ./configure CC="gcc -std=gnu99" CFLAGS="-O0 -g -Wall -pedantic -ffloat-store -fexcess-precision=standard" --without-recommended-packages --disable-byte-compiled-packages --disable-long-double
  ## make
  ## Rdevel
  ## install.packages("bit64")
  ## q("no")
  ## Rdevel CMD INSTALL ~/data.table_1.12.3.tar.gz
  ## Rdevel
  ## .Machine$sizeof.longdouble   # check 0
  ## require(data.table)
  ## require(bit64)
  ## test.data.table()
  ## q("no")
  
  ########################################################################
  #  rchk : https://github.com/kalibera/rchk
  
negative.code: R CMD build .
  R CMD check data.table_1.12.3.tar.gz
  
  
  #####################################################
  #  R-devel with UBSAN, ASAN, strict-barrier, and noLD
  #####################################################
  
  cd ~/build
  