Search path in group_roles not honered for logins

[Ow Mun Heng <Ow.Mun.Heng@xxxxxxx>]

CREATE ROLE db_users
  NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE;
ALTER ROLE db_users SET search_path=mydb, public;

When I create a login,

CREATE ROLE oli LOGIN
  ENCRYPTED PASSWORD 'mXXX'
  NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE;
ALTER ROLE oliver SET search_path=xmms; <---- I have to set this manually
GRANT db_users TO ol;

Why is this such or is this an intended feature?

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match