timeout:time_out/3, introduced in
release 4.10.0, has been corrected.
fd_set_failures/2 did not work.
smt/1 is not supported in the scope of fd_batch/1.
library(tcltk), would crash if the loaded
Tcl/Tk implementation was too new, e.g., for Tcl/Tk 9. Now it throws an
exception.