Users of Cursor, an AI-based coding editor built on the same open-source foundation as Microsoft’s Visual Studio Code (VS Code), are facing new challenges when using popular Microsoft extensions, particularly for C and C++ development. Reports indicate that extensions which previously worked, such as the C/C++ extension, are now broken for some users.
Problems with the C/C++ Extension
A developer recently reported that while version 1.17.62 of the C/C++ extension worked fine, versions 1.18.21 and later do not. This issue is causing frustration among Cursor users, as the extension was a vital tool for developers using C/C++.
Microsoft’s Terms and the VS Code Marketplace
Microsoft’s marketplace terms specify that extensions can only be used with certain Microsoft products and services, including Visual Studio, VS Code, GitHub Codespaces, Azure DevOps, and Azure DevOps Server. This limitation encourages developers to stick with Microsoft’s official distribution, leading to the creation of the Open VSX marketplace. Managed by the Eclipse Foundation, this marketplace provides a more open alternative but has fewer extensions and lower user adoption compared to Microsoft’s official marketplace.
Cursor’s Access to VS Code Extensions
Despite these restrictions, Cursor offers users access to some Microsoft extensions, including the C/C++ extension and C# DevKit, directly from within the Cursor IDE. There’s also an option to import extensions from a VS Code installation. However, users have recently reported issues when trying to use features like Find All References in the C/C++ extension, which results in a pop-up warning about restrictions.
Confusion and Workarounds
Cursor still recommends installing Microsoft’s C++ extension when it detects a compatible project, but developers may face limitations in functionality. As an alternative, developers could consider using the clangd extension, although it has fewer installs (1.7 million) compared to Microsoft’s extension (81 million).
Additionally, Cursor’s documentation guides users on how to install extensions from the Microsoft store using a .vsix file. However, the link to this file is no longer available in the marketplace’s home page for the extension, and developers must often download it directly from the extension’s GitHub repository if it’s open source.
Potential Impact of Agent Mode
Some developers speculate that the change in behavior could be related to the release of Agent Mode in the stable build of VS Code, which is an AI-driven feature that makes Cursor a more direct competitor to VS Code. Microsoft has maintained that VS Code is based on Code-OSS, an open-source project, but with Microsoft-specific customizations released under a separate license.
Compliance Issues and Future Considerations
The issues seem to primarily affect Microsoft’s own extensions, not those from third-party developers. There is speculation that Cursor does not directly link to the marketplace but instead provides access to extensions through its own service, which could explain the new limitations. Developers who rely on Microsoft extensions may need to explore alternatives or adjust to the changing dynamics of the VS Code extension ecosystem.
