How to get error message out of ActiveRecord::Base.connection.raw_connection

I run this code to import a large csv file into a table in Postgres:

  connection = ActiveRecord::Base.connection.raw_connection
  connection.exec(%q[COPY import_xp_raw_bill_details FROM STDIN DELIMITERS ',' CSV])
  data =
  data.each_line {|line| connection.put_copy_data(line)}

In the code, after that in the same method I call the db via AR again to confirm the records loaded (I have confirmed it can be any method, even the most simple AR find… lets say ‘User.all’), and I get the error below (note that I have determined the error is due to the specific file I am importing, as the code works for other files… I would rather though get a real message from Postgres if it is availalble rather than do trial and error to find the issue with the specific file).

(rdb:1) User.all ActiveRecord::StatementInvalid Exception: PGError: ERROR: current transaction is aborted, commands ignored until end of transaction block : SELECT “users”.* FROM “users”

From experience I know this means I made the god of PG unhappy and I am not allowed back for now as a punishment. However I can not seem to retrieve a specific error from the connection object above. I do see an ActiveRecord::Base.connection.raw_connection#error_message method, but it returns an empty string.

Anyone have an idea where else to look… I have read the whole method list for this object (ActiveRecord::Base.connection.raw_connection) and tried everything that looked promising.