R opportunistically links to libunwind

[barracuda156]

Looks like R may link to libunwind and Macports is unaware of that. Should a conflict be declared or dependency?

1: package ‘grDevices’ in options("defaultPackages") was not found 
2: package ‘graphics’ in options("defaultPackages") was not found 
3: package ‘stats’ in options("defaultPackages") was not found 
Error: package or namespace load failed for ‘graphics’ in dyn.load(file, DLLpath = DLLpath, ...):
 unable to load shared object '/opt/local/Library/Frameworks/R.framework/Versions/4.3/Resources/library/grDevices/libs/grDevices.so':
  dlopen(/opt/local/Library/Frameworks/R.framework/Versions/4.3/Resources/library/grDevices/libs/grDevices.so, 0x0006): Library not loaded: /opt/local/lib/libunwind.1.dylib
  Referenced from: <52F935DD-BFC2-3E7A-AB7A-CAADC0D3AB87> /opt/local/Library/Frameworks/R.framework/Versions/4.3/Resources/library/grDevices/libs/grDevices.so
  Reason: tried: '/opt/local/lib/libunwind.1.dylib' (no such file), '/System/Volumes/Preboot/Cryptexes/OS/opt/local/lib/libunwind.1.dylib' (no such file), '/opt/local/lib/libunwind.1.dylib' (no such file), '/opt/local/Library/Frameworks/R.framework/Resources/lib/libunwind.1.dylib' (no such file)

[ryandesign (Ryan Carsten Schmidt)]

libunwind is a standard macOS library. Having it installed with MacPorts will probably cause all sorts of software to try to use it. It should be removed or moved to a directory that is not searched by the linker by default. See comment:ticket:68609:3, #66250.

[barracuda156]

On Sonoma I get this now, for example:

/opt/local/bin/clang++-mp-15 -std=gnu++17 -dynamiclib -Wl,-headerpad_max_install_names -undefined dynamic_lookup -L/opt/local/Library/Frameworks/R.framework/Resources/lib -L/opt/local/lib -Wl,-headerpad_max_install_names -Wl,-rpath,/opt/local/lib/libgcc -Wl,-syslibroot,/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk -arch arm64 -o CompQuadForm.so imhof.o qfc.o registerDynamicSymbol.o ruben.o -F/opt/local/Library/Frameworks/R.framework/.. -framework R -Wl,-framework -Wl,CoreFoundation
ld: warning: reexported library with install name '/opt/local/lib/libunwind.1.dylib' found at '/opt/local/lib/libunwind.1.dylib' couldn't be matched with any parent library and will be linked directly
installing to /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_R_R-CompQuadForm/R-CompQuadForm/work/build/00LOCK-CompQuadForm/00new/CompQuadForm/libs
** R