When can Developers cancel a Sprint?

According to the Scrum Guide, a Sprint can be canceled before the Sprint time-box is over. Only the Product Owner has the authority to cancel the Sprint, although he or she may do so under influence from the stakeholders, the Developers, or the Scrum Master. A Sprint would be canceled if the Sprint Goal becomes obsolete. This might occur if the company changes direction or if market or technology conditions change. In general, a Sprint should be canceled if it no longer makes sense given the circumstances. But, due to the short duration of Sprints, cancellation rarely makes sense. Developers cannot cancel a Sprint on their own, even if they face challenges or difficulties with the selected Product Backlog items, the functional expectations, the technical dependencies, or the Product Owner’s availability. Instead, they should collaborate with the Product Owner and the Scrum Master to find the best way to deliver value within the Sprint and adapt to the changing situation.

References:

The Scrum Guide

Understanding and Applying the Scrum Framework

Professional Scrum Product Owner™ I Certification