cc1plus.exe of bundled mingw-w64 segfaults

[Shao, Cheng]

I managed to build a ghc bindist which bundles gcc 8.2.0, and
cc1plus.exe works as intended now. However, I'm getting linker errors
like:

```
    ghc.EXE: unable to load package `ghc-prim-0.5.3'
    ghc.EXE:  |
C:\Users\Think\AppData\Local\Programs\stack\x86_64-windows\ghc-8.7.20180902\mingw\x86_64-w64-mingw32\lib\libmingw32.a:
unknown symbol `__acrt_iob_func'
    ghc.EXE:  |
C:\Users\Think\AppData\Local\Programs\stack\x86_64-windows\ghc-8.7.20180902\mingw\x86_64-w64-mingw32\lib\libmingwex.a:
unknown symbol `__mingw_raise_matherr'
    ghc.EXE:  |
C:\Users\Think\AppData\Local\Programs\stack\x86_64-windows\ghc-8.7.20180902\lib\ghc-prim-0.5.3\HSghc-prim-0.5.3.o:
unknown symbol `exp'
```

I checked ghc-prim.cabal, but saw that on Windows ghc-prim already
links with libmingw32.a/libmingwex.a, which is supposed to provide
`__mingw_raise_matherr`, etc. Is there any other library to link, or
something else has gone wrong? Thank you.
__
On Sun, Sep 2, 2018 at 10:06 PM, Shao, Cheng <cheng.shao at tweag.io> wrote:
> Hi folks,
>
> I'm building a Haskell/C++ hybrid project with a recent revision of
> ghc on Windows, and noticed that cc1plus.exe always segfaults. The
> same code builds fine on AppVeyor however and currently I have no clue
> why it ceases to work on my machine. Is anyone else experiencing a
> similar problem? I'm not sure if it's worth a trac ticket.
>
> Using cc1plus.exe from a newer version of mingw-w64-x86_64-gcc works
> on my machine, but weird linker errors arise when I attempt to use the
> newer gcc toolchain to override the bundled one. Is there a way to
> manually specify mingw-w64 tarball version/urls when configuring ghc?
> I notice there's an "--enable-distro-toolchain" flag, does it work
> with building a bindist? Thank you.
>
> Regards,
> Shao Cheng