identifier "SIG_BLOCK" is undefined

Dear all,

I have problems building Cmake 3.11.2 with Intel 17up5 compilers. The same build with GCC 4.8.5 works without any issues. So it looks like this is something specific to Intel compilers, as opposed to being a bug in CMake config/build.

Error I have are:

59 errors found in build log:
     1411        ^
     1412
     1413    /tmp/iwtm108/spack-stage/spack-stage-p0hLlQ/cmake-3.11.2/Source/kwsys/ProcessUNIX.c(1726): warning #266: function "sigprocmask" declared implicitly
     1414        if (sigprocmask(SIG_BLOCK, &mask, &old_mask) < 0) {
     1415            ^
     1416
  >> 1417    /tmp/iwtm108/spack-stage/spack-stage-p0hLlQ/cmake-3.11.2/Source/kwsys/ProcessUNIX.c(1726): error: identifier "SIG_BLOCK" is undefined
     1418        if (sigprocmask(SIG_BLOCK, &mask, &old_mask) < 0) {
     1419                        ^
     1420
     1421    /tmp/iwtm108/spack-stage/spack-stage-p0hLlQ/cmake-3.11.2/Source/kwsys/ProcessUNIX.c(1745): warning #266: function "sigprocmask" declared implicitly
     1422          sigprocmask(SIG_SETMASK, &old_mask, 0);
     1423          ^
     1424
  >> 1425    /tmp/iwtm108/spack-stage/spack-stage-p0hLlQ/cmake-3.11.2/Source/kwsys/ProcessUNIX.c(1745): error: identifier "SIG_SETMASK" is undefined
     1426          sigprocmask(SIG_SETMASK, &old_mask, 0);
     1427                      ^
     1428
     1429    /tmp/iwtm108/spack-stage/spack-stage-p0hLlQ/cmake-3.11.2/Source/kwsys/ProcessUNIX.c(1787): warning #266: function "sigprocmask" declared implicitly
     1430          sigprocmask(SIG_SETMASK, &old_mask, 0);
     1431          ^
     1432
  >> 1433    /tmp/iwtm108/spack-stage/spack-stage-p0hLlQ/cmake-3.11.2/Source/kwsys/ProcessUNIX.c(1787): error: identifier "SIG_SETMASK" is undefined
     1434          sigprocmask(SIG_SETMASK, &old_mask, 0);
     1435                      ^
     1436
     1437    /tmp/iwtm108/spack-stage/spack-stage-p0hLlQ/cmake-3.11.2/Source/kwsys/ProcessUNIX.c(1407): warning #266: function "kill" declared implicitly
     1438                kill(-cp->ForkPIDs[i], SIGINT);
     1439                ^

Regards, 

Denis.