[Bug libstdc++/108027] mcf thread model causes build issues for multilibs of x86_64-w64-mingw32 target

[lh_mouse at 126 dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108027

--- Comment #1 from LIU Hao <lh_mouse at 126 dot com> ---
I need some information about this though:


When multilib is enabled, does GCC still link programs with `-lmsvcrt`? There
seems to be only reference to msvcrt:

  gcc/config/i386/mingw32.h:187:   -lmoldname -lmingwex -lmsvcrt -lkernel32 "
MCFGTHREAD_SPEC

which is followed by `MCFGTHREAD_SPEC`.


If GCC links against libmcfgthread in both m32 and m64, then I suspect there is
only one issue: You forgot to install mcfgthread. I don't know whether libtool
has builtin macros for multilib builds; by default libraries are installed into
`<prefix>/lib` and you have to copy them into `<prefix>/lib32` and
`<prefix>/lib64`, respectively.