Stock libxml2 broken on XCODE 8

[jeroen]

After upgrading OSX 10.11 to Xcode 8, I can no longer install xml2 from source. Travis logs show the same problem for xcode8 + stock libxml2

clang++ -dynamiclib -Wl,-headerpad_max_install_names -undefined dynamic_lookup -single_module -multiply_defined suppress -L/Library/Frameworks/R.framework/Resources/lib -L/usr/local/lib -o xml2.so RcppExports.o connection.o xml2_doc.o xml2_init.o xml2_namespace.o xml2_node.o xml2_url.o xml2_xpath.o xml_push.o -L/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/lib -lxml2 -lz -lpthread -licucore -lm -F/Library/Frameworks/R.framework/.. -framework R -Wl,-framework -Wl,CoreFoundation
ld: file not found: /usr/lib/system/libsystem_symptoms.dylib for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I suspect this is a bug in OS-X because Xcode 8 uses MacOSX10.12.sdk however I am still on 10.11. Hopefully the upgrade to OSX 10.12 will include a rebuild of libxml2 which works with Xcode 8.

I just can't figure out where libsystem_symptoms.dylib gets linked from. @s-u @krlmlr

[jeroen]

This is a problem with Xcode 8 on OS-X 10.11. It has been resolved in OS-X 10.12.

• OS X v10.11.x 'El Capitan,' Xcode 8, and the Command Line Tools (Or, Rather, the Lack Thereof…) (Tracking) Homebrew/brew#972
• https://stat.ethz.ch/pipermail/r-sig-mac/2016-September/012040.html

[karrtikiyer]

@jeroenooms : went through the posts above however it is not very clear how I can fix this issue on 10.11 without upgrading to 10.12, can you please help or guide me on this?

[jeroen]

The easiest way is just installing the binary package from CRAN. If you really want to install from source you can use this workaround: https://stat.ethz.ch/pipermail/r-sig-mac/2016-September/012046.html

[jimhester]

Can confirm BDR's workaround works fine, just ran into this myself.

[jeroen]

I incorporated this workaround in our travis file: 92a9ec9