Problems with rake db:schema:dump and Ruby 1.8.5


I’ve got a couple of development machines, and on one of them I
recently updated Ruby to 1.8.5 (the other’s on 1.8.4), then rebuilt
gems and installed rails etc etc.

Apart from that the two machines are identical, and my apps work fine
on each.

However, I’m working on a new app, and was trying to run some unit
tests on the machine with Ruby 1.8.5, and noticed that even though the
test db was there it was bailing with errors about undefined

So I ran rake db:test:prepare, and still had problems until I noticed
that db/schema.rb is empty except for:

# This file is autogenerated. Instead of editing this file, please

use the
# migrations feature of ActiveRecord to incrementally modify your
database, and
# then regenerate this schema definition.

ActiveRecord::Schema.define(:version => 14) do


This doesn’t happen on the machine running Ruby 1.8.4. Is this a known
bug and is there a workaround? Can’t find anything online.



Oh, and just to provide some more info, calling the rake task with –
trace on both machines produces the identical output below:

** Invoke db:schema:dump (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:schema:dump
Loaded suite /usr/local/bin/rake

Finished in XXXXXX seconds.

One more update. The problem is not with Ruby 1.8.5, but with the
Postgres gem I think. It turned out that the other difference between
the two development boxes is the version of Postgres (8.2.1 on the
broken one, 8.1.0 on the other).

Pointing to the database on the broken box from the working one
reproduces the issue on that box.