Realm: compile time error in shm.cc

[mariodirenzo]

Hello, the latest version of control replication fails to compile on one of the computers that use for CI of HTR with the following error:

/home/gitlab-runner/legion/runtime/realm/shm.cc: In static member function 'static bool Realm::SharedMemoryInfo::create(Realm::SharedMemoryInfo&, size_t, const char*, int)':
/home/gitlab-runner/legion/runtime/realm/shm.cc:104:42: error: 'MFD_CLOEXEC' was not declared in this scope; did you mean 'FD_CLOEXEC'?
  104 |       fd = syscall(SYS_memfd_create, "", MFD_CLOEXEC);
      |                                          ^~~~~~~~~~~
      |                                          FD_CLOEXEC
make[2]: *** [runtime/CMakeFiles/RealmRuntime.dir/realm/shm.cc.o] Error 1
make[1]: *** [runtime/CMakeFiles/RealmRuntime.dir/all] Error 2
make: *** [all] Error 2

At a first look, this seems related to the latest changes to the shared memory management

@elliottslaughter, can you please add this issue to #1032 with high priority?

[elliottslaughter]

@muraj is this yours?

[cmelone]

I will add that this is the second compilation error uncovered by our CI in the past few days.

[muraj]

Yeah, this is actually older and related to the first one in that conda compilers seem to have a weird libc implementation. I pushed a change to master to fix this, should be okay now.

[mariodirenzo]

Thanks for working on a fix. The issue is solved.