From @jonathanstowe

I had no idea whether it was possible to construct a regex object by other means than rx//
so I tried​:

say Regex.new(pattern => "hshss")

This results in (gdb bt)​:

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7bb8541 in MVM_string_utf8_encode_substr ()
  from /home/jonathan/.rakudobrew/moar-nom/install/lib/libmoar.so
(gdb) bt
#​0 0x00007ffff7bb8541 in MVM_string_utf8_encode_substr ()
  from /home/jonathan/.rakudobrew/moar-nom/install/lib/libmoar.so
#​1 0x00007ffff7b64471 in MVM_io_syncstream_write_str ()
  from /home/jonathan/.rakudobrew/moar-nom/install/lib/libmoar.so
#​2 0x00007ffff7b62932 in MVM_io_write_string ()
  from /home/jonathan/.rakudobrew/moar-nom/install/lib/libmoar.so
#​3 0x00007ffff7b2fb49 in MVM_interp_run ()
  from /home/jonathan/.rakudobrew/moar-nom/install/lib/libmoar.so
#​4 0x00007ffff7bd87ab in MVM_vm_run_file ()
  from /home/jonathan/.rakudobrew/moar-nom/install/lib/libmoar.so
#​5 0x000000000040101f in main ()

This with​:

This is perl6 version 2015.05-76-g94eed8f built on MoarVM version 2015.05

From @usev6

This was fixed with commits c79bcc5698 and 2cc3afe985.

I added a test to S05-metasyntax/regex.t with commit Raku/roast@e2259973be

I'm closing this ticket as 'resolved'.

@usev6 - Status changed from 'new' to 'resolved'