Hi all,
  Currently, we link both the release and debug versions of phobos and druntime with the debug version of MSVC's LIBC multithreaded: LIBCMTD.lib.
Actually, while reading CMakeLists.txt, I see that the release and debug runtime libs are compiled with the same C-flags and LD-flags. Only the D flags are different.
Is this intentional, or would we rather like to link with LIBCMT.lib in release mode?

To help the discussion, here some observations (it surprised me):
ldc2 test.d           --> links with phobos2-ldc.lib
ldc2 -d-debug test.d  --> links with phobos2-ldc.lib
ldc2 -g test.d        --> links with phobos2-ldc-debug.lib
So "-g" selects between runtime debug/release runtime versions, and "-d-debug" sets the "debug condition" to true (see http://dlang.org/version.html)

thanks,
 Johan

Note that druntime 2.067 explicitly links with the release version libcmt.lib  (druntime/src/rt/monitor_.d(58): "pragma(lib, "libcmt.lib");").

LDC-merge2.067 does not link executables on Windows because of a library conflict due to that pragma. LDC does not need that pragma, and commenting out that pragma avoids the conflict.

On Monday, 6 April 2015 at 15:38:57 UTC, Johan Engelen wrote:
> ldc2 test.d           --> links with phobos2-ldc.lib
> ldc2 -d-debug test.d  --> links with phobos2-ldc.lib
> ldc2 -g test.d        --> links with phobos2-ldc-debug.lib

I'd say, that's expected: -debug is for source-level debugging, that's why it's not reflected in the kind of generated code; -g is codegen-level debugging, that's why it links with appropriately compiled runtime.