c++ - Two problems with Address Sanitizer

Question

In a hobby project I use the address sanitizer (-fsanitize=address) and g++-6 (Homebrew GCC 6.3.0_1) 6.3.0.

I got an error that I do not understand, which is:

==94266==AddressSanitizer CHECK failed: ../../../../libsanitizer/asan/asan_globals.cc:146 "((AddrIsAlignedByGranularity(g->size_with_redzone))) != (0)" (0x0, 0x0) #0 0x10b60cd3d in __asan::AsanCheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) (libasan.3.dylib+0x5dd3d) #1 0x10b612be3 in __sanitizer::CheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) (libasan.3.dylib+0x63be3)

After playing around for a while, I noticed that I am using regex in two different classes, and if I remove either one of them, the problem disappears. I want to understand why and what I can do about that.

So, my next attempt is to build a minimum example of the problem, and I came up with the following:

// a.cpp

#include <iostream>
#include <regex>
#include <string>

using namespace std;

void a(const std::string &s)
{
    regex re_a("foo (.+)");
    smatch pieces;

    if (regex_match(s, pieces, re_a))
    {
        cout << "foo with " << pieces[1].str() << endl;
    }
}

// m.cpp
#include <string>
#include <regex>

void a(const std::string &s);

int main(int argc, char** argv)
{
    std::regex re("123");

    a("foo test 123");
}

If I compile with "g++-6 -fsanitize=address a.cpp m.cpp" and then run "./a.out", the program hangs forever, while "g++-6 a.cpp m.cpp" followed by "./a.out" just works as expected.

This is not the exactly what I wanted to demonstrate here (as I do not get the AddressSanitizer CHECK failed error), but the problems could be related?

I do see a few of these as well, just to be complete: ld: warning: direct access in function '__GLOBAL__sub_D_00099_0_a.cpp' from file '/var/folders/lq/t18hc5bn0c5bxf7h7nn609f40000gp/T//ccTC4rgj.o' to global weak symbol 'std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > std::__cxx11::regex_traits<char>::lookup_collatename<char const*>(char const*, char const*) const::__collatenames' from file '/var/folders/lq/t18hc5bn0c5bxf7h7nn609f40000gp/T//ccTC4rgj.o' means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.

edit: forgot to mention one detail I also noticed. If I comment out the regex var 're' in m.cpp, the problem also disappears completely.

Thanks for any help!