[MacPorts] #62426: libc++: using a newer libc++ to build software on older macos systems

[MacPorts]

#62426: libc++: using a newer libc++ to build software on older macos systems
-------------------------------------+--------------------
  Reporter:  kencu                   |      Owner:  kencu
      Type:  enhancement             |     Status:  closed
  Priority:  Normal                  |  Milestone:
 Component:  ports                   |    Version:
Resolution:  fixed                   |   Keywords:
      Port:  libcxx macports-libcxx  |
-------------------------------------+--------------------

Comment (by RJVB):

 An example. KDevelop5 entirely rebuilt against libc++ 9.0.1 installed in
 /opt/local/lib, including libc++.dylib . None of KDevelop's dependencies
 are built against this libc++ version, and I don't have
 DYLD_INSERT_LIBRARIES set in the environment.

 {{{
 > otool -L /opt/local/lib/libc++.dylib | fgrep libc++
 /opt/local/lib/libc++.dylib:
         /opt/local/lib/libc++.1.dylib (compatibility version 1.0.0,
 current version 9.0.1)
         /opt/local/lib/libc++abi.1.dylib (compatibility version 1.0.0,
 current version 9.0.1)

 > otool -L
 /Applications/MacPorts/KF5/kdevelop.app/Contents/MacOS/kdevelop.bin  |
 fgrep libc++
         /opt/local/lib/libc++.1.dylib (compatibility version 1.0.0,
 current version 9.0.1)

 > otool -L
 /opt/local/libexec/qt5/Library/Frameworks/QtCore.framework/QtCore | fgrep
 libc++
         /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current
 version 120.0.0)

 > env DYLD_PRINT_LIBRARIES=1
 /Applications/MacPorts/KF5/kdevelop.app/Contents/MacOS/kdevelop.bin --ps
 |& fgrep libc++ &
 dyld: loaded: /opt/local/lib/libc++.1.dylib
 dyld: loaded: /usr/lib/libc++.1.dylib
 dyld: loaded: /usr/lib/libc++abi.dylib
 dyld: loaded: /opt/local/lib/libc++abi.1.dylib
 dyld: loaded: /usr/lib/libc++.1.dylib
 dyld: loaded: /usr/lib/libc++abi.dylib
 dyld: loaded: /usr/lib/libc++.1.dylib
 dyld: loaded: /usr/lib/libc++abi.dylib
 <snip>

 > lsof +c 0 | fgrep kdevelop | fgrep libc++
 kdevelop.bin          69337 bertin  txt      REG                1,1
 2223932  9538392 /opt/local/lib/libc++.1.dylib
 kdevelop.bin          69337 bertin  txt      REG                1,1
 617328  9538394 /opt/local/lib/libc++abi.1.dylib
 kdevelop.bin          76697 bertin  txt      REG                1,1
 2223932  9538392 /opt/local/lib/libc++.1.dylib
 kdevelop.bin          76697 bertin  txt      REG                1,1
 617328  9538394 /opt/local/lib/libc++abi.1.dylib
 }}}

 Here I used `lsof` to obtain the files open in/by KDevelop but the open
 files list given by the Activity Monitor shows the same result: only a
 single version of both libc++ components is kept opened (the newest
 version), despite multiple load attempts of the system versions (one for
 each module/library being loaded).

-- 
Ticket URL: <https://trac.macports.org/ticket/62426#comment:53>
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