https://issues.dlang.org/show_bug.cgi?id=20297

          Issue ID: 20297
           Summary: ld: warning: building for macOS
           Product: D
           Version: D2
          Hardware: All
                OS: Mac OS X
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: doob@me.com

With Xcode 11 (or on macOS 10.15) linking an executable with an object file
built with DMD results in the following warning (one for each object file being
linked):

ld: warning: building for macOS, but linking in object file
(~/.dvm/compilers/dmd-2.088.0/osx/lib/libphobos2.a(format_5df_c43.o)) built for

The issue is that the linker is looking for a load command in each object file which contains the platform, platform version and SDK version. Clang outputs this load command but the DMD doesn't.

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