Can't make decoderbufs with PostgreSQL11

When I start to make decoderbufs project, always got below error:
-bash-4.2$ make && make install

gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -fPIC -std=c11 -I/usr/local/include -I. -I./ -I/usr/pgsql-11/include/server -I/usr/pgsql-11/include/internal -D_GNU_SOURCE -I/usr/include/libxml2 -I/usr/include -c -o src/decoderbufs.o src/decoderbufs.c

src/decoderbufs.c: In function ‘pg_decode_startup’:

src/decoderbufs.c:113:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]

ListCell *option;

^

src/decoderbufs.c: In function ‘set_datum_value’:

src/decoderbufs.c:462:7: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]

Decoderbufs_Point dp = DECODERBUFSPOINT_INIT;

^

src/decoderbufs.c:479:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]

int len = strlen(output);

^

src/decoderbufs.c: In function ‘tuple_to_tuple_msg’:

src/decoderbufs.c:502:10: error: incompatible types when assigning to type ‘Form_pg_attribute’ from type ‘FormData_pg_attribute’

attr = tupdesc->attrs[natt];

^

src/decoderbufs.c:509:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]

Decoderbufs_DatumMessage datum_msg = DECODERBUFSDATUM_MESSAGE_INIT;

^

src/decoderbufs.c:512:27: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]

datum_msg.column_name = quote_identifier(NameStr(attr->attname));

^

src/decoderbufs.c:521:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]

Oid typoutput;

^

make: *** [src/decoderbufs.o] Error 1

-bash-4.2$ exit