Open source software ecosystems are composed of a variety of stakeholders including but not limited to non-profit organizations, volunteer contributors, users, and corporations. The needs and motivations of these stakeholders are often diverse, unknown, and sometimes even conflicting given the engagement and investment of both volunteers and corporate actors. Given this, it is not clear how open source communities identify and engage with their stakeholders, understand their needs, and hold themselves accountable to those needs. We convened 24 expert scholars and practitioners studying and working with open source software communities for an exploratory workshop discussion on these ideas. The workshop titled "Accountability and Open Source Software Ecosystems" was organized on Oct 14-15 on campus in Carnegie Mellon University, Pittsburgh, PA. The purpose of this in-person workshop was to initiate conversations that explore important and urgent questions related to the role of accountability in open source software ecosystems, and to inspire an exciting research agenda and meaningful stakeholder engagement ideas for practitioners.