==13511== 80 bytes in 1 blocks are definitely lost in loss record 160 of 643
==13511==    at 0x25A96B: malloc (in /usr/local/lib/valgrind/vgpreload_memcheck-amd64-freebsd.so)
==13511==    by 0x25AAB4: realloc (in /usr/local/lib/valgrind/vgpreload_memcheck-amd64-freebsd.so)
==13511==    by 0x2DDA39F: __wt_realloc (os_alloc.c:75)
==13511==    by 0x2DBE0AD: __wt_txn_modify (txn.i:26)
==13511==    by 0x2DBDF88: __wt_update_alloc (row_modify.c:323)
==13511==    by 0x2DBCF61: __wt_row_modify (row_modify.c:129)
==13511==    by 0x2D97BD7: __wt_btcur_insert (bt_cursor.c:312)
==13511==    by 0x2DC8A25: __curfile_insert (cur_file.c:175)
==13511==    by 0x2DD8E10: __wt_metadata_insert (meta_table.c:142)
==13511==    by 0x2DDF7F9: __create_file (schema_create.c:54)
==13511==    by 0x2DE0B04: __wt_schema_create (schema_create.c:395)
==13511==    by 0x2DEA02C: __session_create (session_api.c:256)

import wiredtiger, wttest
from helper import key_populate, value_populate

class test_f(wttest.WiredTigerTestCase):
    def test_f(self):
        self.session.create(
            'file:x', 'key_format=S,value_format=S')
        cursor = self.session.open_cursor('file:x', None)
        for i in range(1, 10):
            cursor.set_key(key_populate(cursor, i))
            cursor.set_value("======== VALUE =======")
            cursor.insert()
        cursor.close()
        self.session.checkpoint()


if __name__ == '__main__':
    wttest.run()