does lsm3 work with Postgres 12 or Greenplum?

I got following error while making it:

lsm3.h:46:9: error: unknown type name ‘BTOptions’
   46 |         BTOptions   nbt_opts;       /* Standard B-Tree options */
      |         ^~~~~~~~~
lsm3.c: In function ‘lsm3_truncate_index’:
lsm3.c:209:32: error: implicit declaration of function ‘BuildDummyIndexInfo’; did you mean ‘BuildIndexInfo’? [-Werror=implicit-function-declaration]
  209 |         IndexInfo* indexInfo = BuildDummyIndexInfo(index);
      |                                ^~~~~~~~~~~~~~~~~~~
      |                                BuildIndexInfo
lsm3.c:209:32: warning: initialization of ‘IndexInfo *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
lsm3.c: In function ‘lsm3_merge_indexes’:
lsm3.c:236:37: error: ‘BTREE_AM_OID’ undeclared (first use in this function); did you mean ‘BTREE_MAGIC’?
  236 |         base_index->rd_rel->relam = BTREE_AM_OID;
      |                                     ^~~~~~~~~~~~
      |                                     BTREE_MAGIC
lsm3.c:236:37: note: each undeclared identifier is reported only once for each function it appears in
lsm3.c:243:21: error: implicit declaration of function ‘BTreeTupleIsPosting’ [-Werror=implicit-function-declaration]
  243 |                 if (BTreeTupleIsPosting(itup))

postgrespro / lsm3

does lsm3 work with Postgres 12 or Greenplum? #6