rake undefined method `fields' for nil:NilClass on database seed

Question

When i try to do

rake db:reset

or

rake db:drop
rake db:create
rake db:schema:load
rake db:seed

I randomly get a NoMethodError: undefined method 'fields' for nil:NilClass when the seed occurs. Here's one:

[1m[35m (186.0ms)[0m  INSERT INTO "schema_migrations" (version) VALUES ('20130318105449')
[1m[36m (187.0ms)[0m  [1mINSERT INTO "schema_migrations" (version) VALUES ('20130319154146')[0m
[1m[35m (189.0ms)[0m  INSERT INTO "schema_migrations" (version) VALUES ('20130322132730')
[1m[36m (104.0ms)[0m  [1mINSERT INTO "schema_migrations" (version) VALUES ('20130322142814')[0m
NoMethodError: undefined method `fields' for nil:NilClass:               SELECT COUNT(*)
          FROM pg_class c
          LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
          WHERE c.relkind in ('v','r')
          AND c.relname = 'schema_migrations'
          AND n.nspname = ANY (current_schemas(false))

Here's an other one:

[1m[35m (39.0ms)[0m  BEGIN
[1m[36mCategory Exists (107.0ms)[0m  [1mSELECT 1 AS one FROM "categories" WHERE "categories"."hash" = 'cat1' LIMIT 1[0m
[1m[35mSQL (124.0ms)[0m  INSERT INTO "categories" ("category_id", "created_at", "label", "hash", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id"  [["category_id", 58], ["created_at", Mon, 25 Mar 2013 15:07:53 CET +01:00], ["label", "Cat1"], ["hash", "cat1"], ["updated_at", Mon, 25 Mar 2013 15:07:53 CET +01:00]]
[1m[36m (117.0ms)[0m  [1mCOMMIT[0m
[1m[35m (162.0ms)[0m  BEGIN
[1m[36mCategory Exists (136.0ms)[0m  [1mSELECT 1 AS one FROM "categories" WHERE "categories"."hash" = 'cat2' LIMIT 1[0m
[1m[35mSQL (104.0ms)[0m  INSERT INTO "categories" ("created_at", "label", "hash", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id"  [["created_at", Mon, 25 Mar 2013 15:07:53 CET +01:00], ["label", "Cat2"], ["hash", "cat2"], ["updated_at", Mon, 25 Mar 2013 15:07:53 CET +01:00]]
[1m[36m (99.0ms)[0m  [1mCOMMIT[0m
[1m[35m (108.0ms)[0m  BEGIN
[1m[36mCategory Exists (173.0ms)[0m  [1mSELECT 1 AS one FROM "categories" WHERE "categories"."hash" = 'cat3' LIMIT 1[0m
NoMethodError: undefined method `fields' for nil:NilClass: SELECT  1 AS one FROM "categories"  WHERE "categories"."hash" = 'cat3' LIMIT 1

I really do not understand where this can be coming from. Sometimes i don't even have an error and everything is perfectly inserted. After doing some tests it seems that it depends on the speed of insertion. If i execute this from my development server, it almost always succeed. If i execute this remotly from my computer, it almost always fails.

I'm using ruby 1.9.3 locally and ruby 2 on my development server. On both i'm using rails4 (edge) and my driver is postgresql (pg, no version specified)

Canonicate

Answer 1

I'm experiencing this problem as well on rails4 (edge) and postgres. I'm running into it on a solr:reindex, so I don't think its necessarily related to insertions in any way. I'll update this when I figure out whats going wrong.

Edit: Try updating to rails revision 1a838ccda4a31bb023985f6c977e6bc3e238cda9, it solved my problem.

This is the github issue on it: https://github.com/rails/rails/issues/9710

I found it after a quick git bisect. It's definitely fixed in git now.

Coimbatore

Usually you'd add this as a comment. Seeing this is your first post, I'll upvote it so you'll gain the ability to add comments. Welcome to Stackoverflow! :-D – Burrill

Ah, thanks for the heads up. Nice to know the etiquette. As far as the issue goes, I was able to recreate the bug on a test project using (1..10000).each { Foobar.first }, on the same revision that my project was using. I updated my test-project to revision 1a838ccda4a31bb023985f6c977e6bc3e238cda9 and the problem went away. I'm confident once I update my project to the same revision the problem should be fixed. – Coimbatore