[MacPorts] #58895: gcc9: search path for standard libraries is incomplete/incorrect

[MacPorts]

#58895: gcc9: search path for standard libraries is incomplete/incorrect
---------------------+----------------------
  Reporter:  prbuen  |      Owner:  (none)
      Type:  defect  |     Status:  reopened
  Priority:  Normal  |  Milestone:
 Component:  ports   |    Version:
Resolution:          |   Keywords:
      Port:  gcc9    |
---------------------+----------------------

Comment (by Serge3leo):

 Replying to [comment:36 kencu]:
 > I don't see any gcc ports with this defect at present.

 For example:
 gcc10-10.3.0_1.darwin_19.x86_64.tbz2:/opt/local/lib/gcc10/gcc/x86_64
 -apple-darwin19/10.3.0/plugin/include/configargs.h
     --with-pkgversion='MacPorts gcc10 10.3.0_1' --with-
 sysroot=/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk";

 gcc9-9.4.0_1.darwin_19.x86_64.tbz2:/opt/local/lib/gcc9/gcc/x86_64-apple-
 darwin19/9.4.0/plugin/include/configargs.h
     --with-pkgversion='MacPorts gcc9 9.4.0_1' --with-
 sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk";

 gcc8-8.5.0_1.darwin_19.x86_64.tbz2:/opt/local/lib/gcc8/gcc/x86_64-apple-
 darwin19/8.5.0/plugin/include/configargs.h
     --with-pkgversion='MacPorts gcc8 8.5.0_1' --with-
 sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk";

 ...

 For darwin_19 (macOS Catalina 10.15), which path to the SDK will be
 correct?
 * /Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk
 *
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk

 For source build package - all right. "configure" detect SDK root.

 But for precompiled packages, we need the root SDK location on the build
 machine and on the user's machine to match.

 > We do not want every gcc port to depend on MacOSX10.15.sdk, certainly.
 The would be appropriate only for one os version.

 We can use "macosx_deployment_target" to choose between dependencies:
 MacOSX10.6.sdk ... Mac OS X 10.15.sdk

-- 
Ticket URL: <https://trac.macports.org/ticket/58895#comment:37>
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