have_func: checking for rb_io_extract_modeenc() in ruby/io.h... -------------------- no

"gcc -o conftest -I/usr/include/x86_64-linux-gnu/ruby-2.5.0 -I/usr/include/ruby-2.5.0/ruby/backward -I/usr/include/ruby-2.5.0 -I. -Wdate-time -D_FORTIFY_SOURCE=2   -g -O2 -fdebug-prefix-map=/build/ruby2.5-F4mxqA/ruby2.5-2.5.5=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC conftest.c  -L. -L/usr/lib/x86_64-linux-gnu -L. -Wl,-z,relro -Wl,-z,now -fstack-protector -rdynamic -Wl,-export-dynamic     -lruby-2.5  -lpthread -lgmp -ldl -lcrypt -lm   -lc"
/usr/lib/ruby/2.5.0/mkmf.rb:395: warning: Insecure world writable dir /go/bin in PATH, mode 040777
checked program was:
/* begin */
1: #include "ruby.h"
2: 
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */

"gcc -o conftest -I/usr/include/x86_64-linux-gnu/ruby-2.5.0 -I/usr/include/ruby-2.5.0/ruby/backward -I/usr/include/ruby-2.5.0 -I. -Wdate-time -D_FORTIFY_SOURCE=2   -g -O2 -fdebug-prefix-map=/build/ruby2.5-F4mxqA/ruby2.5-2.5.5=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC conftest.c  -L. -L/usr/lib/x86_64-linux-gnu -L. -Wl,-z,relro -Wl,-z,now -fstack-protector -rdynamic -Wl,-export-dynamic     -lruby-2.5  -lpthread -lgmp -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:15:57: error: ‘rb_io_extract_modeenc’ undeclared (first use in this function); did you mean ‘rb_io_oflags_fmode’?
 int t(void) { void ((*volatile p)()); p = (void ((*)()))rb_io_extract_modeenc; return !p; }
                                                         ^~~~~~~~~~~~~~~~~~~~~
                                                         rb_io_oflags_fmode
conftest.c:15:57: note: each undeclared identifier is reported only once for each function it appears in
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: #include <ruby/io.h>
 4: 
 5: /*top*/
 6: extern int t(void);
 7: int main(int argc, char **argv)
 8: {
 9:   if (argc > 1000000) {
10:     printf("%p", &t);
11:   }
12: 
13:   return 0;
14: }
15: int t(void) { void ((*volatile p)()); p = (void ((*)()))rb_io_extract_modeenc; return !p; }
/* end */

"gcc -o conftest -I/usr/include/x86_64-linux-gnu/ruby-2.5.0 -I/usr/include/ruby-2.5.0/ruby/backward -I/usr/include/ruby-2.5.0 -I. -Wdate-time -D_FORTIFY_SOURCE=2   -g -O2 -fdebug-prefix-map=/build/ruby2.5-F4mxqA/ruby2.5-2.5.5=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC conftest.c  -L. -L/usr/lib/x86_64-linux-gnu -L. -Wl,-z,relro -Wl,-z,now -fstack-protector -rdynamic -Wl,-export-dynamic     -lruby-2.5  -lpthread -lgmp -ldl -lcrypt -lm   -lc"
/usr/bin/ld: /tmp/cc9483RH.o: in function `t':
/sdk/clients/client/ruby/vendor/bundle/ruby/2.5.0/gems/stringio-3.0.4/ext/stringio/conftest.c:16: undefined reference to `rb_io_extract_modeenc'
collect2: error: ld returned 1 exit status
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: #include <ruby/io.h>
 4: 
 5: /*top*/
 6: extern int t(void);
 7: int main(int argc, char **argv)
 8: {
 9:   if (argc > 1000000) {
10:     printf("%p", &t);
11:   }
12: 
13:   return 0;
14: }
15: extern void rb_io_extract_modeenc();
16: int t(void) { rb_io_extract_modeenc(); return 0; }
/* end */

--------------------