Valgrind error when running a test in [Tux] csv module

gistfile1.txt

    t/45_eol.t ........... ==25299== Memcheck, a memory error detector
    ==25299== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
    ==25299== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
    ==25299== Command: /home/dogbert/.rakudobrew/versions/moar-master/install/bin/rakudo-m -Ilib t/45_eol.t
    ==25299== 
    t/45_eol.t ........... 726/? ==25299== Invalid read of size 4
    ==25299==    at 0x4B00A4F: cache_sep_info (decode_stream.c:639)
    ==25299==    by 0x4B00A4F: MVM_string_decode_stream_sep_from_strings (decode_stream.c:698)
    ==25299==    by 0x4ACAA97: MVM_decoder_set_separators (Decoder.c:199)
    ==25299==    by 0x4A4E9B4: MVM_interp_run (interp.c:5158)
    ==25299==    by 0x109621: main (main.c:392)
    ==25299==  Address 0x8e58abc is 4 bytes before a block of size 0 alloc'd
    ==25299==    at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
    ==25299==    by 0x4B008F1: MVM_malloc (alloc.h:2)
    ==25299==    by 0x4B008F1: MVM_string_decode_stream_sep_from_strings (decode_stream.c:690)
    ==25299==    by 0x4ACAA97: MVM_decoder_set_separators (Decoder.c:199)
    ==25299==    by 0x4A4E9B4: MVM_interp_run (interp.c:5158)
    ==25299==    by 0x109621: main (main.c:392)