[MacPorts] #59727: gcc9: fails to link properly (-lSystem no found)

[MacPorts]

#59727: gcc9: fails to link properly (-lSystem no found)
------------------------+--------------------
  Reporter:  akimd      |      Owner:  (none)
      Type:  defect     |     Status:  new
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.6.2
Resolution:             |   Keywords:
      Port:  gcc8 gcc9  |
------------------------+--------------------

Comment (by akimd):

 Hi Ken,

 Yes, you are right, GCC8 and 9 lack
 /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/lib.

 {{{
 $ gcc-mp-7 -Wl,-v foo.c
 collect2 version 7.5.0
 /opt/local/bin/ld -syslibroot
 /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/ -dynamic -arch
 x86_64 -macosx_version_min 10.14.7 -weak_reference_mismatches non-weak -o
 a.out -L/opt/local/lib/gcc7/gcc/x86_64-apple-darwin18/7.5.0
 -L/opt/local/lib/gcc7/gcc/x86_64-apple-darwin18/7.5.0/../../.. -v
 /var/folders/5y/lz6sht194vz_k1p88510k3yc0000gs/T//ccvee4AI.o
 -no_compact_unwind -lSystem -lgcc_ext.10.5 -lgcc -lSystem
 -no_compact_unwind
 @(#)PROGRAM:ld  PROJECT:ld64-520
 BUILD 18:38:01 Oct 11 2019
 configured to support archs: armv6 armv7 armv7s arm64 arm64e arm64_32 i386
 x86_64 x86_64h armv6m armv7k armv7m armv7em
 Library search paths:
         /opt/local/lib/gcc7/gcc/x86_64-apple-darwin18/7.5.0
         /opt/local/lib/gcc7
         /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/lib
 Framework search paths:
 /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/
  /opt/local/bin/nm -n
 /var/folders/5y/lz6sht194vz_k1p88510k3yc0000gs/T//ccvee4AI.o
 }}}

 {{{
 $ gcc-mp-9 -Wl,-v foo.c
 collect2 version 9.2.0
 /opt/local/bin/ld -syslibroot
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/
 -dynamic -arch x86_64 -macosx_version_min 10.14.0
 -weak_reference_mismatches non-weak -o a.out
 -L/opt/local/lib/gcc9/gcc/x86_64-apple-darwin18/9.2.0
 -L/opt/local/lib/gcc9/gcc/x86_64-apple-darwin18/9.2.0/../../.. -v
 /var/folders/5y/lz6sht194vz_k1p88510k3yc0000gs/T//cc2FOO1B.o
 -no_compact_unwind -lSystem -lgcc_ext.10.5 -lgcc -lSystem
 @(#)PROGRAM:ld  PROJECT:ld64-520
 BUILD 18:38:01 Oct 11 2019
 configured to support archs: armv6 armv7 armv7s arm64 arm64e arm64_32 i386
 x86_64 x86_64h armv6m armv7k armv7m armv7em
 Library search paths:
         /opt/local/lib/gcc9/gcc/x86_64-apple-darwin18/9.2.0
         /opt/local/lib/gcc9
 Framework search paths:
 ld: library not found for -lSystem
 collect2: error: ld returned 1 exit status
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/59727#comment:2>
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