instructure/canvas-lms · error

require course

Error message

require course

What it means

Courses::TimetableEventBuilder#initialize requires a course: the builder generates calendar events scoped to a course (optionally a section), so constructing it without a course raises 'require course' immediately.

Solutions

1. Resolve the Course and pass course: course to the builder.
2. Validate the course lookup succeeded before constructing the builder and surface a user-facing error if not.
3. If operating on a section only, still pass its course: builder.new(course: section.course, course_section: section).

Example fix

// before
builder = TimetableEventBuilder.new(course_section: section)

// after
raise 'course not found' unless course
builder = TimetableEventBuilder.new(course: course, course_section: section)

raise 'course not found' if course.nil?
TimetableEventBuilder.new(course: course, course_section: section)

def buildable?(course, section = nil)
  course.is_a?(Course)
end

When it happens

Trigger: Courses::TimetableEventBuilder.new(course_section: section) with course omitted; passing course: nil from a caller whose lookup failed; passing only course_section even though the builder keys on course.

Common situations: Timetable importers where the Course lookup by sis_id/name returned nil and the nil was forwarded; misuse assuming course_section alone suffices; refactors that renamed a local variable used as the course: argument.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• timetable codes can't be blank
• Course pace is deleted
• Course pace is not deleted
• Course required
• invalid association

AI-assisted analysis of instructure/canvas-lms@1c9f0bb801 (2026-09-15). Data as JSON: /api/errors/104cdf14c7bf2f9d. Report an issue: GitHub.

Appendix: source

Thrown at app/models/courses/timetable_event_builder.rb:27

# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.

module Courses
  class TimetableEventBuilder
    # builds calendar events for a course (or course sections) according to a timetable

    attr_reader :course, :course_section, :event_context, :errors

    def initialize(course: nil, course_section: nil)
      raise "require course" unless course

      @course = course
      @course_section = course_section
      @event_context = course_section || course
    end

    # generates individual events from a simplified "timetable" between the course/section start and end dates
    # :weekdays - days of week (0-Sunday, 1-Monday, 2-Tuesday, 3-Wednesday, 4-Thursday, 5-Friday, 6-Saturday)
    # :start_time - basically any time that can be parsed by the magic (e.g. "11:30 am")
    # :end_time - ditto
    # :location_name (optional)
    def generate_event_hashes(timetable_hashes)
      time_zone = course.time_zone
      event_hashes = []
      timetable_hashes.each do |timetable_hash|
        course_start_at = timetable_hash[:course_start_at]
        course_end_at = timetable_hash[:course_end_at]

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