core.sys contains packages with system-specific D interface files (ports of header files). As...

...found out that there is a core.sys.posix module only by rgrepping under /usr...

...digging I found isatty defined under core.sys.posix.unistd, and I suppose I can...

...exception.d   math.d        runtime.d 
    stdc/         sys/          time.d

So, then I uninstalled dmd...

...504a652c6c47

real	0m14.427s
user	1m19.347s
sys     0m0.124s

i've got similar performances...

...average :
real	0m1.999s
user	0m9.810s
sys	0m0.148

btw Rust version is even...

C++ version :
real	0m3.587s
user	0m9.211s
sys	0m7.341s

...156s
sys	0m0.181s

C version gives :
real	0m1.892s
user	0m9.087s
sys	0m0...

...core/sys/unwind.d
    M win32.mak
    M win64.mak

  Log Message:
  -----------
  add core.sys...

...0m7.342s
sys 0m0.905s

for D
real 0m35.356s
user 0m35.149s
sys 0m0...