Undefined references when compiling

I built OCC as static libraries, and now I want to build a static binary for portability.  My code is:

// STEP Read Methods
#include <STEPControl_Reader.hxx>
#include <TopoDS_Shape.hxx>
// STL Read & Write Methods
#include <StlAPI_Writer.hxx>
#include <BRepMesh_IncrementalMesh.hxx>
// Bounding Box
#include <BRepBndLib.hxx> //bb
#include <Bnd_Box.hxx> //bb
// Volume
#include <BRepGProp.hxx> //vol
#include <GProp_GProps.hxx> //vol


#include <iostream>

int step2stl(char *in, char *out) {

  double Xmin, Ymin, Zmin, Xmax, Ymax, Zmax; //bb

  // Read from STEP
  STEPControl_Reader reader;
  IFSelect_ReturnStatus stat = reader.ReadFile(in);

  Standard_Integer NbRoots = reader.NbRootsForTransfer();
  Standard_Integer NbTrans = reader.TransferRoots();
  TopoDS_Shape Original_Solid = reader.OneShape();


  // get vol
  GProp_GProps gprops;
  BRepGProp::VolumeProperties(Original_Solid, gprops);
  double volume = gprops.Mass();

  // Get bounding box dimensions
  Bnd_Box B; //bb

  BRepBndLib::Add(Original_Solid, B); //bb
  B.Get(Xmin, Ymin, Zmin, Xmax, Ymax, Zmax); //bb

  //bb print bounding box params
  // X
  std::cout << "Xmin: " << Xmin << "\n";
  std::cout << "Xmax: " << Xmax << "\n";
  std::cout << "Xsize: "<< Xmax-Xmin << "\n";
  // Y
  std::cout << "Ymin: " << Ymin << "\n";
  std::cout << "Ymax: " << Ymax << "\n";
  std::cout << "Ysize: "<< Ymax-Ymin << "\n";
  // Z
  std::cout << "Zmin: " << Zmin << "\n";
  std::cout << "Zmax: " << Zmax << "\n";
  std::cout << "Zsize: "<< Zmax-Zmin << "\n";
  // Volume
  std::cout << "Volume: "<< volume << "\n";
  // end marker for parsing
  std::cout <<"end\n";


  // Write to STL
  StlAPI_Writer stlWriter = StlAPI_Writer();
  //stlWriter.SetCoefficient(0.0001);
  stlWriter.ASCIIMode() = Standard_False;

  BRepMesh_IncrementalMesh Mesh( Original_Solid, 0.6 );

  Mesh.Perform();

  stlWriter.Write( Original_Solid, out);

  return 0;
}


Standard_Integer main (int argc, char *argv[]) {
  if (argc != 3) {
      std::cerr << "Usage: " << argv[0] << " file.step file.stl" << std::endl;
      return 1;
  }

  return step2stl(argv[1], argv[2]);
}

I'm using clang++ on Ubuntu to compile.

Before, I built the OCC dynamic library, and this code worked fine:

clang++ -std=c++11 -stdlib=libc++ -I/usr/local/include/oce -I/usr/include -ggdb3   -c -o main.o main.cpp

clang++ -std=c++11 -stdlib=libc++ -L/usr/local/lib -L/usr/lib -lTKBRep -lTKG2d -lTKG3d -lTKGeomBase -lTKMath -lTKMesh -lTKSTEP -lTKSTEP209 -lTKTopAlgo -lTKSTEPAttr -lTKSTEPBase -lTKSTL -lTKXSBase -lTKernel  -o step2stl main.o

Now, I want to compile from the static library, and I enter this:

clang++ -std=c++11 -stdlib=libc++ -I/usr/local/include/opencascade -I/usr/include -ggdb3   -c -o main.o main.cpp -static

clang++ -std=c++11 -stdlib=libc++ -L/usr/local/lib -L/usr/lib -L/usr/local/include/opencascade -lTKBRep -lTKG2d -lTKG3d -lTKGeomBase -lTKMath -lTKMesh -lTKSTEP -lTKSTEP209 -lTKTopAlgo -lTKSTEPAttr -lTKSTEPBase -lTKSTL -lTKXSBase -lTKernel  -o step2stl main.o -static

From here I get many errors:

/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(iostream.cpp.o):(.data.rel.ro._ZTINSt3__110__stdinbufIcEE[_ZTINSt3__110__stdinbufIcEE]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(iostream.cpp.o):(.data.rel.ro._ZTINSt3__110__stdinbufIwEE[_ZTINSt3__110__stdinbufIwEE]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(iostream.cpp.o):(.data.rel.ro._ZTINSt3__111__stdoutbufIcEE[_ZTINSt3__111__stdoutbufIcEE]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(iostream.cpp.o):(.data.rel.ro._ZTINSt3__111__stdoutbufIwEE[_ZTINSt3__111__stdoutbufIwEE]+0x0): undefined reference to `vtable for __cxxabiv1::__si_class_type_info'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::__cloc()':
(.text+0x2c): undefined reference to `__cxa_guard_acquire'
(.text+0x56): undefined reference to `__cxa_guard_release'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::__time_put::~__time_put()':
(.text+0x1a04): undefined reference to `__cxa_guard_acquire'
(.text+0x1a2e): undefined reference to `__cxa_guard_release'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::__throw_runtime_error(char const*)':
(.text+0x3dcd): undefined reference to `__cxa_allocate_exception'
(.text+0x3de2): undefined reference to `typeinfo for std::runtime_error'
(.text+0x3de9): undefined reference to `std::runtime_error::~runtime_error()'
(.text+0x3df1): undefined reference to `__cxa_throw'
(.text+0x3dfc): undefined reference to `__cxa_free_exception'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::locale::__imp::__imp(unsigned long)':
(.text+0x5b7e): undefined reference to `__cxa_guard_acquire'
(.text+0x5bac): undefined reference to `__cxa_guard_release'
(.text+0x5bbd): undefined reference to `__cxa_guard_acquire'
(.text+0x5beb): undefined reference to `__cxa_guard_release'
(.text+0x5bfc): undefined reference to `__cxa_guard_acquire'
(.text+0x5c2a): undefined reference to `__cxa_guard_release'
(.text+0x5c3b): undefined reference to `__cxa_guard_acquire'
(.text+0x5c69): undefined reference to `__cxa_guard_release'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::locale::__imp::__imp(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, unsigned long)':
(.text+0x696b): undefined reference to `__cxa_guard_acquire'
(.text+0x69a8): undefined reference to `__cxa_guard_release'
(.text+0x6a1b): undefined reference to `__cxa_guard_abort'
(.text+0x6b68): undefined reference to `__cxa_begin_catch'
(.text+0x6bbb): undefined reference to `__cxa_rethrow'
(.text+0x6bc3): undefined reference to `__cxa_end_catch'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::locale::classic()':
(.text+0x6c0c): undefined reference to `__cxa_guard_acquire'
(.text+0x6c45): undefined reference to `__cxa_guard_release'
(.text+0x6c56): undefined reference to `__cxa_guard_abort'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::locale::__imp::__imp(std::__1::locale::__imp const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int)':
(.text+0x7786): undefined reference to `__cxa_begin_catch'
(.text+0x77d9): undefined reference to `__cxa_rethrow'
(.text+0x77e1): undefined reference to `__cxa_end_catch'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/../../../x86_64-linux-gnu/libc++.a(locale.cpp.o): In function `std::__1::locale::__imp::__imp(std::__1::locale::__imp const&, std::__1::locale::__imp const&, int)':
(.text+0x7b01): undefined reference to `__cxa_begin_catch'
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#many lines later...
(.text+0x1d21): undefined reference to `pthread_mutex_unlock'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/libgcc_eh.a(unwind-dw2-fde-dip.o): In function `__register_frame_info_bases.part.6':
(.text+0x1834): undefined reference to `pthread_mutex_unlock'
/usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0/libgcc_eh.a(unwind-dw2-fde-dip.o): In function `__register_frame_info_table_bases':
(.text+0x1944): undefined reference to `pthread_mutex_unlock'
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Please help.  My end goal is to create a static portable binary.

Thanks