Now \d show tablespace of indices per discussion.
test=# \d e
Table "public.e"
Column | Type | Modifiers
--------+---------+-----------
i | integer | not null
j | integer | not null
k | integer |
Indexes:
"e_pkey" PRIMARY KEY, btree (i, j), tablespace "haha"
"ei" btree (i)
"ej" btree (j), tablespace "haha"
"ek" btree (k)
Tablespace: "haha"