Decidim: PG::UndefinedFunction: ERROR: operator does not exist: jsonb - unknown

[israelbuitron]

I was installing an instance of Decidim, and when I execute bin/rails db:migrate, it throws these messages:

...
== 20190404024613 RenameMaximumVotesPerProposalToThresholdPerProposal: migrating 
-- execute("UPDATE decidim_components\nSET settings = jsonb_set(\n  settings::jsonb,\n  array['global'],\n  (settings->'global')::jsonb - 'maximum_votes_per_proposal' || jsonb_build_object('threshold_per_proposal', settings->'global'->'maximum_votes_per_proposal')\n  )\nWHERE manifest_name = 'proposals'\n")
rails aborted!
StandardError: An error has occurred, this and all later migrations canceled:

PG::UndefinedFunction: ERROR:  operator does not exist: jsonb - unknown
LINE 5:   (settings->'global')::jsonb - 'maximum_votes_per_proposal'...
                                      ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
: UPDATE decidim_components
SET settings = jsonb_set(
  settings::jsonb,
  array['global'],
  (settings->'global')::jsonb - 'maximum_votes_per_proposal' || jsonb_build_object('threshold_per_proposal', settings->'global'->'maximum_votes_per_proposal')
  )
WHERE manifest_name = 'proposals'

Error messages point to method up at line 6 in db/migrate/20190404024613_rename_maximum_votes_per_proposal_to_threshold_per_proposal.decidim.rb:

  def up
    execute <<~SQL
      UPDATE decidim_components
      SET settings = jsonb_set(
        settings::jsonb,
        array['global'],
        (settings->'global')::jsonb - 'maximum_votes_per_proposal' || jsonb_build_object('threshold_per_proposal', settings->'global'->'maximum_votes_per_proposal')
        )
      WHERE manifest_name = 'proposals'
    SQL
  end

[mrcasals]

Hi @israelbuitron! What version of PostgreSQL are you using?

Minimum required version is 9.5, as per https://github.com/decidim/decidim/blob/master/docs/manual-installation.md

[israelbuitron]

@mrcasals Yes, I have installed PostgreSQL 9.5:

psql -V
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
    LANGUAGE = (unset),
    LC_ALL = (unset),
    LC_CTYPE = "UTF-8",
    LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to a fallback locale ("en_US.UTF-8").
psql (PostgreSQL) 9.5.16

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. @carolromero & @xabier feel free to chime in.