build_failure for rubysl-yaml

cat /home/production/api.medycation.com/shared/bundle/ruby/2.1.0/extensions/x86_64-linux/2.1.0-static/rubysl-yaml-2.0.4/gem_make.out
/usr/local/bin/ruby extconf.rb
checking for st.h... yes
creating Makefile

make "DESTDIR=" clean

make "DESTDIR="
compiling emitter.c
compiling gram.c
compiling token.c
token.re: In function ‘sycklex_yaml_utf8’:
token.re:541:36: warning: variable ‘lvl’ set but not used [-Wunused-but-set-variable]
compiling node.c
compiling bytecode.c
compiling rubyext.c
rubyext.c: In function ‘mktime_do’:
rubyext.c:292:19: warning: unused variable ‘offset’ [-Wunused-variable]
         const int offset = padding + 1;
                   ^
rubyext.c: In function ‘rb_syck_load_handler’:
rubyext.c:664:5: warning: implicit declaration of function ‘rb_hash_size’ [-Wimplicit-function-declaration]
     rb_hash_aset(bonus->data, rb_hash_size(bonus->data), obj);
     ^
rubyext.c: In function ‘rb_syck_err_handler’:
rubyext.c:684:12: warning: format ‘%d’ expects argument of type ‘int’, but argument 5 has type ‘long int’ [-Wformat=]
            p->lineptr);
            ^
rubyext.c: In function ‘syck_const_find’:
rubyext.c:1047:5: warning: implicit declaration of function ‘rb_ary_size’ [-Wimplicit-function-declaration]
     for ( i = 0; i < rb_ary_size(tparts); i++ ) {
     ^
rubyext.c: In function ‘syck_scalar_value_set’:
rubyext.c:19:56: error: ‘struct RString’ has no member named ‘ptr’
 #define syck_copy_string(val) syck_strndup(RSTRING(val)->ptr, RSTRING_LEN(val))
                                                        ^
rubyext.c:1481:27: note: in expansion of macro ‘syck_copy_string’
     node->data.str->ptr = syck_copy_string(val);
                           ^
rubyext.c: In function ‘syck_seq_initialize’:
rubyext.c:1509:15: warning: variable ‘node’ set but not used [-Wunused-but-set-variable]
     SyckNode *node;
               ^
rubyext.c: In function ‘syck_node_type_id_set’:
rubyext.c:19:56: error: ‘struct RString’ has no member named ‘ptr’
 #define syck_copy_string(val) syck_strndup(RSTRING(val)->ptr, RSTRING_LEN(val))
                                                        ^
rubyext.c:1741:25: note: in expansion of macro ‘syck_copy_string’
         node->type_id = syck_copy_string(type_id);
                         ^
make: *** [rubyext.o] Error 1

make failed, exit code 2