The AddLookupValueMatchToHostAndHostgroup migration added in #11425 doesn't populate the lookup_value_matcher field added to the host table. It only updates the updated_at timestamp:

This causes all FQDN-specific matchers to no longer match, which could lead to severe misconfigurations.

2015-08-26T12:48:36 [sql] [D]    (0.1ms)  begin transaction
==  AddLookupValueMatchToHostAndHostgroup: migrating ==========================
-- add_column(:hosts, :lookup_value_matcher, :string)
2015-08-26T12:48:36 [sql] [D]    (0.7ms)  ALTER TABLE "hosts" ADD "lookup_value_matcher" varchar(255)
   -> 0.0013s
-- add_column(:hostgroups, :lookup_value_matcher, :string)
2015-08-26T12:48:36 [sql] [D]    (0.3ms)  ALTER TABLE "hostgroups" ADD "lookup_value_matcher" varchar(255)
   -> 0.0006s
2015-08-26T12:48:36 [sql] [D]   Host::Managed Load (0.3ms)  SELECT "hosts".* FROM "hosts" WHERE "hosts"."type" IN ('Host::Managed') AND "hosts"."type" = 'Host::Managed' ORDER BY "hosts"."id" ASC LIMIT 100
2015-08-26T12:48:36 [sql] [D]   Nic::Base Load (0.1ms)  SELECT "nics".* FROM "nics" WHERE "nics"."host_id" = 82 ORDER BY identifier
2015-08-26T12:48:37 [sql] [D]    (0.1ms)  UPDATE "hosts" SET "updated_at" = '2015-08-26 11:48:37.009783' WHERE "hosts"."type" IN ('Host::Managed') AND "hosts"."id" = 82
2015-08-26T12:48:37 [sql] [D]   Nic::Base Load (0.1ms)  SELECT "nics".* FROM "nics" WHERE "nics"."host_id" = 109 ORDER BY identifier
2015-08-26T12:48:37 [sql] [D]   Domain Load (0.1ms)  SELECT "domains".* FROM "domains" WHERE "domains"."id" = 4 ORDER BY domains.name LIMIT 1
2015-08-26T12:48:37 [sql] [D]    (0.2ms)  UPDATE "hosts" SET "updated_at" = '2015-08-26 11:48:37.058461' WHERE "hosts"."type" IN ('Host::Managed') AND "hosts"."id" = 109
2015-08-26T12:48:37 [sql] [D]   Nic::Base Load (0.1ms)  SELECT "nics".* FROM "nics" WHERE "nics"."host_id" = 110 ORDER BY identifier
2015-08-26T12:48:37 [sql] [D]   Domain Load (0.1ms)  SELECT "domains".* FROM "domains" WHERE "domains"."id" = 6 ORDER BY domains.name LIMIT 1
2015-08-26T12:48:37 [sql] [D]    (0.1ms)  UPDATE "hosts" SET "updated_at" = '2015-08-26 11:48:37.062754' WHERE "hosts"."type" IN ('Host::Managed') AND "hosts"."id" = 110
2015-08-26T12:48:37 [sql] [D]   Nic::Base Load (0.1ms)  SELECT "nics".* FROM "nics" WHERE "nics"."host_id" = 118 ORDER BY identifier
2015-08-26T12:48:37 [sql] [D]   Domain Load (0.1ms)  SELECT "domains".* FROM "domains" WHERE "domains"."id" = 6 ORDER BY domains.name LIMIT 1
2015-08-26T12:48:37 [sql] [D]    (0.1ms)  UPDATE "hosts" SET "updated_at" = '2015-08-26 11:48:37.065953' WHERE "hosts"."type" IN ('Host::Managed') AND "hosts"."id" = 118
2015-08-26T12:48:37 [sql] [D]   Nic::Base Load (0.1ms)  SELECT "nics".* FROM "nics" WHERE "nics"."host_id" = 168 ORDER BY identifier
2015-08-26T12:48:37 [sql] [D]   Domain Load (0.1ms)  SELECT "domains".* FROM "domains" WHERE "domains"."id" = 6 ORDER BY domains.name LIMIT 1
2015-08-26T12:48:37 [sql] [D]    (0.1ms)  UPDATE "hosts" SET "updated_at" = '2015-08-26 11:48:37.069205' WHERE "hosts"."type" IN ('Host::Managed') AND "hosts"."id" = 168
2015-08-26T12:48:37 [sql] [D]   Nic::Base Load (0.2ms)  SELECT "nics".* FROM "nics" WHERE "nics"."host_id" = 170 ORDER BY identifier
2015-08-26T12:48:37 [sql] [D]   Domain Load (0.1ms)  SELECT "domains".* FROM "domains" WHERE "domains"."id" = 13 ORDER BY domains.name LIMIT 1
2015-08-26T12:48:37 [sql] [D]    (0.1ms)  UPDATE "hosts" SET "updated_at" = '2015-08-26 11:48:37.072978' WHERE "hosts"."type" IN ('Host::Managed') AND "hosts"."id" = 170

sqlite> select id,lookup_value_matcher from hosts;
82|
109|
110|
118|
168|
170|

Adding a Host.reset_column_information call seems to make it work properly.