When installing Squid4 on Leopard Intel, MacPorts tries (and fails) to build libcxx

[Wowfunhappy (Jonathan)]

The Squid Proxy is particularly useful on old versions of OS X, because it can be used to fix HTTPS problems. I'm trying to build it in a clean, Intel Leopard VM, with a default copy of macports.conf.

For whatever reason, MacPorts is attempting to pull in libcxx when I install squid4, and libcxx cannot be built on Leopard out of the box. As a result, the port fails to install:

:notice:build --->  Building libcxx
:debug:build Executing org.macports.build (libcxx)
:debug:build Environment: 
:debug:build CC='/usr/bin/gcc-4.2'
:debug:build CC_PRINT_OPTIONS='YES'
:debug:build CC_PRINT_OPTIONS_FILE='/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/.CC_PRINT_OPTIONS'
:debug:build CPATH='/opt/local/include'
:debug:build CXX='/usr/bin/g++-4.2'
:debug:build DEVELOPER_DIR='/Developer'
:debug:build LIBRARY_PATH='/opt/local/lib'
:debug:build MACOSX_DEPLOYMENT_TARGET='10.5'
:debug:build RC_CFLAGS='-arch i386 -arch ppc -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxxabi-5.0.1.src/include -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxx-5.0.1.src/include -Os'
:debug:build RC_ProjectSourceVersion='5.0.1'
:debug:build RC_XBS='1'
:debug:build TRIPLE='-apple-darwin9'
:info:build Executing:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/build" && /usr/bin/make -j4 -w all LIBCXXABI_PATH=/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxxabi-5.0.1.src LIBCXX_PATH=/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxx-5.0.1.src LIBCXXABI_DYLIB_PATH=/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/build/libc++abi.dylib 
:debug:build system:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/build" && /usr/bin/make -j4 -w all LIBCXXABI_PATH=/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxxabi-5.0.1.src LIBCXX_PATH=/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxx-5.0.1.src LIBCXXABI_DYLIB_PATH=/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/build/libc++abi.dylib 
:info:build make: Entering directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/build'
:info:build cd /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxxabi-5.0.1.src/lib && ./buildit
:info:build + for FILE in '../src/*.cpp'
:info:build + /usr/bin/g++-4.2 -c -g -O3 -arch i386 -arch ppc -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxxabi-5.0.1.src/include -I/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_libcxx/libcxx/work/libcxx-5.0.1.src/include -Os -std=c++11 -stdlib=libc++ -nostdinc++ -fstrict-aliasing -Wstrict-aliasing=2 -Wsign-conversion -Wshadow -Wconversion -Wunused-variable -Wmissing-field-initializers -Wchar-subscripts -Wmismatched-tags -Wmissing-braces -Wshorten-64-to-32 -Wsign-compare -Wstrict-aliasing=2 -Wstrict-overflow=4 -Wunused-parameter -Wnewline-eof -D_LIBCPP_BUILDING_LIBRARY -I../include ../src/abort_message.cpp
:info:build cc1plus: error: unrecognized command line option "-Wsign-conversion"
:info:build cc1plus: error: unrecognized command line option "-Wmismatched-tags"
:info:build cc1plus: error: unrecognized command line option "-std=c++11"
:info:build cc1plus: error: unrecognized command line option "-stdlib=libc++"
:info:build cc1plus: error: unrecognized command line option "-Wsign-conversion"
:info:build cc1plus: error: unrecognized command line option "-Wmismatched-tags"
:info:build cc1plus: error: unrecognized command line option "-std=c++11"
:info:build cc1plus: error: unrecognized command line option "-stdlib=libc++"
:info:build fatal error: lipo: can't figure out the architecture type of: /opt/local/var/macports/build/

This is fundamentally the same issue reported here: ​https://trac.macports.org/ticket/57911. The question is, why is libcxx being used in the first place?

I don't believe this is actually an issue with squid, but kencu asked that I open a new ticket.