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Frequently Asked Questions

What is the minimum version for GCC?​

GCC 9.4. C++17 support is enabled by default in GCC 11; it can be explicitly selected in earlier versions with the -std=c++17 command-line flag or -std=gnu++17 to enable GNU extensions as well. See C++17 Support in GCC for the details. Use spack install gcc first if your system has GCC 4. It will install GCC 12.2.0 by default. Then, run spack compiler find to use the newly installed gcc.

Can I run Hermes on Mac?​

No. macOS lacks several system calls that Hermes components use:

  • fopen64 / fseeko64
  • O_DIRECT / O_TMPFILE
  • gethostbyname_r
  • _STAT_VER

Does Hermes run on Linux only?​

Yes. Hermes uses the fixed /proc code:

inline std::string GetFilenameFromFD(int fd) {
  char proclnk[kMaxPathLen];
  char filename[kMaxPathLen];
  snprintf(proclnk, kMaxPathLen, "/proc/self/fd/%d", fd);
  size_t r = readlink(proclnk, filename, kMaxPathLen);
  filename[r] = '\0';
  return filename;
}

Can I run Hermes on Chameleon JupyterLab Server?​

Maybe. However, installation with Spack will fail due to timeout. For older (< 0.8) Hermes, Google OR-Tools installation will fail.

Why do I get mercury->fatal error when I use rpc_protocol = "ofi+verbs"; in configuration file?​

Such error occurs when libfabric is not compiled with verbs support. Try spack install hermes ^libfabric fabrics=rxm,sockets,tcp,udp,verbs.

Why does MPI Adapter fail to compile?​

The MPI-IO adapter only supports MPICH. Use spack install mpi ^mpich to install mpi. Load it with spack load mpi.