Rails 5.2 + webpack - NoMethodError when trying rake assets:precompile

Question

I've been working on a project, I started a re-design of it, and continued developing it on the main branch. I've just gone to rebase & pull the changes from master into the redesign branch, and it's no longer updating the CSS on the changes I've made.

I've tried to clear caches etc. and I then thought I'd try precompiling assets locally to see if that fixed it and I'm getting the below error.

Can anyone shed some light on how I could fix this please? I'm not very familiar with the asset pipeline and I've got stuck.

** Execute assets:precompile
rails aborted!
NoMethodError: undefined method `start_with?' for /\.(?:svg|eot|woff|ttf)$/:Regexp
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/sprockets-4.0.3/lib/sprockets/uri_utils.rb:78:in `valid_asset_uri?'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/sprockets-4.0.3/lib/sprockets/resolve.rb:27:in `resolve'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/sprockets-4.0.3/lib/sprockets/base.rb:79:in `find_asset'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/sprockets-4.0.3/lib/sprockets/base.rb:88:in `find_all_linked_assets'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/sprockets-4.0.3/lib/sprockets/manifest.rb:125:in `each'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/sprockets-4.0.3/lib/sprockets/manifest.rb:125:in `to_a'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/sprockets-4.0.3/lib/sprockets/manifest.rb:125:in `block (2 levels) in find'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/safe_task_executor.rb:24:in `block in execute'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/synchronization/mutex_lockable_object.rb:47:in `block in synchronize'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/synchronization/mutex_lockable_object.rb:47:in `synchronize'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/synchronization/mutex_lockable_object.rb:47:in `synchronize'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/safe_task_executor.rb:22:in `execute'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/promise.rb:564:in `block in realize'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:352:in `run_task'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:343:in `block (3 levels) in create_worker'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:334:in `loop'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:334:in `block (2 levels) in create_worker'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:333:in `catch'
/Users/username/.rbenv/versions/2.7.5/lib/ruby/gems/2.7.0/gems/concurrent-ruby-1.1.10/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:333:in `block in create_worker'
Tasks: TOP => assets:precompile

Development.rb:

# frozen_string_literal: true

Rails.application.configure do
  config.after_initialize do
    # Bullet.enable = true
    # Bullet.sentry = true
    # Bullet.alert = true
    # Bullet.bullet_logger = true
    Bullet.console = true
    Bullet.rails_logger = true
    # Bullet.honeybadger = true
    Bullet.add_footer = true
    # Bullet.skip_html_injection = false
    # Bullet.slack = { webhook_url: 'https://hooks.slack.com/services/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', channel: '#default', username: 'Bullet-notifier' }
  end


  # Must include to get inline SVGs to work in deploy
  config.assets.css_compressor = :scss

  # notifier = Slack::Notifier.new "https://hooks.slack.com/services/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" do
  #   defaults channel: "#bullet",
  #            username: "notifier"
  # end
  
  # Settings specified here will take precedence over those in config/application.rb.

  # In the development environment your application's code is reloaded on
  # every request. This slows down response time but is perfect for development
  # since you don't have to restart the web server when you make code changes.
  config.cache_classes = false
  config.action_mailer.default_url_options = { host: 'localhost:3000' }
  config.action_cable.url = 'ws://localhost:3000/cable'

  config.eager_load = false
  config.consider_all_requests_local = true

  # Enable/disable caching. By default caching is disabled.
  if Rails.root.join('tmp/caching-dev.txt').exist?
    config.action_controller.perform_caching = true

    config.cache_store = :memory_store
    config.public_file_server.headers = {
      'Cache-Control' => "public, max-age=#{2.days.seconds.to_i}"
    }
  else
    config.action_controller.perform_caching = false

    config.cache_store = :null_store
  end

  # Don't care if the mailer can't send.
  config.action_mailer.perform_caching = false
  config.active_support.deprecation = :log
  config.active_record.migration_error = :false
  config.assets.debug = false
  # config.assets.quiet = true
  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
  config.action_mailer.perform_deliveries = true
  config.action_mailer.raise_delivery_errors = true
  config.active_record.dump_schema_after_migration = false
  config.action_mailer.delivery_method = :smtp
  config.action_mailer.default charset: 'utf-8'
  config.action_mailer.preview_path = "#{Rails.root}/lib/mailer_previews"


  # Print deprecation notices to the Rails logger.
  config.active_support.deprecation = :log

  # Raise an error on page load if there are pending migrations.
  config.active_record.migration_error = :page_load

  # Debug mode disables concatenation and preprocessing of assets.
  # This option may cause significant delays in view rendering with a large
  # number of complex assets.

  # Suppress logger output for asset requests.
  # config.assets.quiet = true

  # Raises error for missing translations
  # config.action_view.raise_on_missing_translations = true

  # Use an evented file watcher to asynchronously detect changes in source code,
  # routes, locales, etc. This feature depends on the listen gem.
  config.file_watcher = ActiveSupport::EventedFileUpdateChecker

end