import Foundation leads to a number of issues

[frol]

• Swift uses private __BEGIN_DECLS / __END_DECLS macros from glibc

  It is easy to get fixed: "Q: When compiling something against musl, I get error messages about sys/cdefs.h"

• Swift uses fts.h ("Q: Why is fts.h not included?")

  I have managed to workaround the missing header by creating an empty /usr/includes/fts.h

• Swift uses clang C++ modules, which play poorly with musl libc (error: declaration of 'mode_t' must be imported from module 'SwiftGlibc.POSIX.termios' before it is required)

  The only workaround I found was to remove the #if define's around mode_t definition in /usr/includes/bits/alltypes.h

• Linker fails when linking to Foundation if -static-stdlib flag is present #1

• static-executable hits undefined references on Linux #2