[MacPorts] #57612: libtool does not respect -syslibroot when linking

[MacPorts]

#57612: libtool does not respect -syslibroot when linking
--------------------+--------------------
 Reporter:  kencu   |      Owner:  (none)
     Type:  defect  |     Status:  new
 Priority:  Normal  |  Milestone:
Component:  ports   |    Version:
 Keywords:          |       Port:
--------------------+--------------------
 This ticket is show some of the behaviour I've been noticing when trying
 to build on Mojave `+universal` against the MacOSX10.13.sdk, in particular
 to try to understand why the linking behaviour fails by default.

 I picked a clean example, building `libedit`.

 macports has been installed in `/opt/universal`, and `macports.conf` has
 two entries added:
 {{{
 macosx_deployment_target     10.13
 macosx_sdk_version           10.13
 }}}

 variants.conf has one entry:
 {{{
 +universal
 }}}
 A copy of the MacOSX10.13.sdk is installed in the proper place in Xcode:
 {{{
 $ ls -la
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/
 total 0
 drwxr-xr-x  5 root  wheel  160  8 Nov 21:38 .
 drwxr-xr-x  5 root  wheel  160 19 Oct 18:18 ..
 drwxr-xr-x  7 root  wheel  224 30 Oct 19:25 MacOSX.sdk
 drwxr-xr-x  5 root  wheel  160  8 Nov 21:37 MacOSX10.13.sdk
 lrwxr-xr-x  1 root  wheel   10 25 Sep 22:31 MacOSX10.14.sdk -> MacOSX.sdk
 }}}

 libtool compiles correctly with the proper -isysroot
 {{{
 libtool: compile:  /usr/bin/clang -DHAVE_CONFIG_H -I. -I..
 -I/opt/universal/include
 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk
 -pipe -Os -arch i386
 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk
 -c readline.c -o readline.o >/dev/null 2>&1
 }}}

 The build tries to set up the link correctly. -isysroot and syslibroot are
 sent to libtool, and libtool passes only syslibroot along to clang to
 link, which should work:
 {{{
 /bin/sh ../libtool  --tag=CC   --mode=link /usr/bin/clang  -pipe -Os -arch
 i386
 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk
 -no-undefined -version-info 0:58:0 -L/opt/universal/lib
 -Wl,-headerpad_max_install_names -arch i386
 -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk
 -o libedit.la -rpath /opt/universal/lib chared.lo common.lo el.lo eln.lo
 emacs.lo hist.lo keymacro.lo map.lo chartype.lo parse.lo prompt.lo read.lo
 refresh.lo search.lo sig.lo terminal.lo tty.lo vi.lo wcsdup.lo
 tokenizer.lo tokenizern.lo history.lo historyn.lo filecomplete.lo
 readline.lo literal.lo        -lncurses
 libtool: link: /usr/bin/clang -dynamiclib  -o .libs/libedit.0.dylib
 .libs/chared.o .libs/common.o .libs/el.o .libs/eln.o .libs/emacs.o
 .libs/hist.o .libs/keymacro.o .libs/map.o .libs/chartype.o .libs/parse.o
 .libs/prompt.o .libs/read.o .libs/refresh.o .libs/search.o .libs/sig.o
 .libs/terminal.o .libs/tty.o .libs/vi.o .libs/wcsdup.o .libs/tokenizer.o
 .libs/tokenizern.o .libs/history.o .libs/historyn.o .libs/filecomplete.o
 .libs/readline.o .libs/literal.o   -L/opt/universal/lib -lncurses  -Os
 -arch i386 -Wl,-headerpad_max_install_names -arch i386 -Wl,-syslibroot
 -Wl,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk
 -install_name  /opt/universal/lib/libedit.0.dylib -compatibility_version 1
 -current_version 1.58 -Wl,-single_module
 }}}
 But does not, in the end, work. Instead, the MacOSX10.14.sdk is somehow
 called instead as the syslibroot to do the link, and this is the
 unexpected behaviour, which fails:
 {{{
 ld: warning: The i386 architecture is deprecated for macOS (remove from
 the Xcode build setting: ARCHS)
 ld: warning: ignoring file
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/lib/libSystem.tbd,
 missing required architecture i386 in file
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/lib/libSystem.tbd
 Undefined symbols for architecture i386:
 Undefined symbols for architecture i386:
   "__DefaultRuneLocale", referenced from:
       _ce__isword in chared.o
       _cv__isword in chared.o
       _cv__isWord in chared.o
       _cv_next_word in chared.o
       _cv_prev_word in chared.o
       _cv__endword in chared.o
       _ed_move_to_beg in common.o
       ...
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/57612>
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