can't install gems with Bundler - ruby

Question

Im trying to install wpscan
I have macbook pro 10.9.2
Im running mavericks osx.
I followed the instruction:
git clone https://github.com/wpscanteam/wpscan.git
cd wpscan
and then I'm trying to
sudo gem install bundler && bundle install --without test development
and after that I get this error:
sudo gem install bundler && bundle install --without test development
Successfully installed bundler-1.6.1
Parsing documentation for bundler-1.6.1
1 gem installed
Fetching gem metadata from https://rubygems.org/.........
Fetching additional metadata from https://rubygems.org/..
Resolving dependencies...
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
checking for ffi.h... no
checking for ffi.h in /usr/local/include,/usr/include/ffi... yes
checking for ffi_call() in -lffi... yes
checking for ffi_prep_closure()... yes
checking for ffi_raw_call()... no
checking for rb_thread_blocking_region()... yes
checking for rb_thread_call_with_gvl()... yes
checking for rb_thread_call_without_gvl()... yes
checking for ffi_prep_cif_var()... no
creating extconf.h
creating Makefile
make "DESTDIR="
compiling AbstractMemory.c
compiling ArrayType.c
compiling Buffer.c
compiling Call.c
Call.c:303:5: warning: implicit declaration of function 'rb_thread_call_without_gvl' is invalid in C99 [-Wimplicit-function-declaration]
rbffi_thread_blocking_region(call_blocking_function, data, (void *) -1, NULL);
^
./Thread.h:78:39: note: expanded from macro 'rbffi_thread_blocking_region'
# define rbffi_thread_blocking_region rb_thread_call_without_gvl
^
1 warning generated.
compiling ClosurePool.c
compiling DataConverter.c
DataConverter.c:43:1: warning: control may reach end of non-void function [-Wreturn-type]
}
^
1 warning generated.
compiling DynamicLibrary.c
compiling ffi.c
compiling Function.c
Function.c:479:33: warning: incompatible pointer types passing 'VALUE (void *)' to parameter of type 'void *(*)(void *)' [-Wincompatible-pointer-types]
rb_thread_call_with_gvl(callback_with_gvl, &cb);
^~~~~~~~~~~~~~~~~
Function.c:102:46: note: passing argument to parameter 'func' here
extern void *rb_thread_call_with_gvl(void *(*func)(void *), void *data1);
^
Function.c:563:9: warning: implicit declaration of function 'rb_thread_call_without_gvl' is invalid in C99 [-Wimplicit-function-declaration]
rb_thread_call_without_gvl(async_cb_wait, &w, async_cb_stop, &w);
^
Function.c:738:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
3 warnings generated.
compiling FunctionInfo.c
compiling LastError.c
compiling LongDouble.c
compiling MappedType.c
compiling MemoryPointer.c
compiling MethodHandle.c
compiling Platform.c
compiling Pointer.c
compiling Struct.c
compiling StructByReference.c
compiling StructByValue.c
compiling StructLayout.c
compiling Thread.c
compiling Type.c
compiling Types.c
compiling Variadic.c
linking shared-object ffi_c.bundle
clang: error: unknown argument: '-multiply_definedsuppress' [-Wunused-command-line-argument-hard-error-in-future]
clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
make: *** [ffi_c.bundle] Error 1
Gem files will remain installed in /var/folders/pf/hl1jk3kx5_j2q70fbwyj18180000gn/T/bundler20140407-7061-7v0bbm/ffi-1.9.3/gems/ffi-1.9.3 for inspection.
Results logged to /var/folders/pf/hl1jk3kx5_j2q70fbwyj18180000gn/T/bundler20140407-7061-7v0bbm/ffi-1.9.3/gems/ffi-1.9.3/ext/ffi_c/gem_make.out
An error occurred while installing ffi (1.9.3), and Bundler cannot continue.
Make sure that `gem install ffi -v '1.9.3'` succeeds before bundling.
can anyone help me?
Thanks.

Answer 1

My guess is that this is your problem (here with json, but it appears to be a variant of the same problem): Ruby Gem install Json fails on Mavericks and Xcode 5.1 - unknown argument: '-multiply_definedsuppress'
Long story short: the temporary fix is "ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future gem install [gem]" where [gem] is the particular gem whose command-line argument is causing the crash.