=== If no file names and line numbers are shown below, one can run
            addr2line -Cfie my_exefile my_line_address
    to convert `my_line_address` (e.g., 0x4a6b) into file name and line number.

=== Please note that the line number reported by addr2line may not be accurate.
    One can use
            readelf -wl my_exefile | grep my_line_address'
    to find out the offset for that line.

 0: ./Castro2d.gnu.TEST.MPI.ex() [0x545839]
    amrex::BLBackTrace::print_backtrace_info(_IO_FILE*)
    /raid/testing/castro-gfortran/AMReX//Src/Base/AMReX_BLBackTrace.cpp:104

 1: ./Castro2d.gnu.TEST.MPI.ex() [0x5466c6]
    amrex::BLBackTrace::handler(int)
    /raid/testing/castro-gfortran/AMReX//Src/Base/AMReX_BLBackTrace.cpp:51

 2: ./Castro2d.gnu.TEST.MPI.ex() [0x4a2e20]
    std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_is_local() const
    /usr/include/c++/7/bits/basic_string.h:211
    std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_dispose()
    /usr/include/c++/7/bits/basic_string.h:220
    std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()
    /usr/include/c++/7/bits/basic_string.h:647
    bl_error_cpp_
    /raid/testing/castro-gfortran/AMReX//Src/Base/AMReX.cpp:172

 3: ./Castro2d.gnu.TEST.MPI.ex() [0x6fde36]
    bl_error_
    /raid/testing/castro-gfortran/AMReX//Src/Base/AMReX_BLBoxLib_F.F90:14

 4: ./Castro2d.gnu.TEST.MPI.ex() [0x764487]
    __advection_util_module_MOD_enforce_minimum_density
    /raid/testing/castro-gfortran/Castro//Source/hydro/advection_util_nd.F90:74

 5: ./Castro2d.gnu.TEST.MPI.ex() [0x419a65]
    amrex::MFIter::operator++()
    /raid/testing/castro-gfortran/AMReX//Src/Base/AMReX_MFIter.H:126
    Castro::enforce_min_density(amrex::MultiFab&, amrex::MultiFab&)
    /raid/testing/castro-gfortran/Castro//Source/driver/Castro.cpp:2651

 6: ./Castro2d.gnu.TEST.MPI.ex() [0x41a99d]
    Castro::clean_state(int, amrex::MultiFab&)
    /raid/testing/castro-gfortran/Castro//Source/driver/Castro.cpp:3586 (discriminator 4)

 7: ./Castro2d.gnu.TEST.MPI.ex() [0x41aa7d]
    Castro::clean_state(int)
    /raid/testing/castro-gfortran/Castro//Source/driver/Castro.cpp:3566

 8: ./Castro2d.gnu.TEST.MPI.ex() [0x41c215]
    Castro::expand_state(amrex::MultiFab&, double, int, int)
    /raid/testing/castro-gfortran/Castro//Source/driver/Castro.cpp:3455

 9: ./Castro2d.gnu.TEST.MPI.ex() [0x4201a9]
    Castro::initialize_do_advance(double, double, int, int)
    /raid/testing/castro-gfortran/Castro//Source/driver/Castro_advance.cpp:654

10: ./Castro2d.gnu.TEST.MPI.ex() [0x42041a]
    Castro::do_advance(double, double, int, int)
    /raid/testing/castro-gfortran/Castro//Source/driver/Castro_advance.cpp:202

11: ./Castro2d.gnu.TEST.MPI.ex() [0x424255]
    Castro::advance(double, double, int, int)
    /raid/testing/castro-gfortran/Castro//Source/driver/Castro_advance.cpp:109

12: ./Castro2d.gnu.TEST.MPI.ex() [0x574108]
    amrex::Amr::timeStep(int, double, int, int, double)
    /raid/testing/castro-gfortran/AMReX//Src/Amr/AMReX_Amr.cpp:1926

13: ./Castro2d.gnu.TEST.MPI.ex() [0x56bb3b]
    amrex::Amr::coarseTimeStep(double)
    /raid/testing/castro-gfortran/AMReX//Src/Amr/AMReX_Amr.cpp:2036

14: ./Castro2d.gnu.TEST.MPI.ex() [0x40ac36]
    main
    /raid/testing/castro-gfortran/Castro//Source/driver/main.cpp:132

15: /lib64/libc.so.6(__libc_start_main+0xea) [0x7ff94aa2df2a]
    ??
    ??:0

16: ./Castro2d.gnu.TEST.MPI.ex() [0x41034a]
    _start
    ??:?