Devs sound alarm after Microsoft subtracts C/C++ extension from VS Code forks

Summary

Microsoft's C/C++ extension for Visual Studio Code (VS Code) no longer works with derivative products such as VS Codium and Cursor – and some developers are crying foul. In early April, programmers using VS Codium, an open-source fork of Microsoft's MIT-licensed VS Code, and Cursor, a commercial AI code assistant built from the VS Code codebase, noticed that the C/C++ extension stopped working. The extension adds C/C++ language support, such as Intellisense code completion and debugging, to VS Code. The removal of these capabilities from competing tools breaks developer workflows, hobbles the editor, and arguably hinders competition. The breaking change appears to have occurred with the release of v1.24.5 on April 3, 2025. Following the April update, attempts to install the C/C++ extension outside of VS Code generate this error message: "The C/C++ extension may be used only with Microsoft Visual Studio, Visual Studio for Mac, Visual Studio Code, Azure DevOps, Team Foundation Server, and successor Microsoft products and services to develop and test your applications." Microsoft has forbidden the use of its extensions outside of its own software products since at least September 2020, when the current licensing terms were published. But it hasn't enforced those terms in its C/C++ extension with an environment check in its binaries until now. (Microsoft's PyLance extension for Python coding is said to have exhibited this behavior for years, preventing its use in VS Code forks.) The latest releases of the specific extensions no longer work in Cursor or other non-MSFT editors Michael Truell, co-founder and CEO of Anysphere, which makes Cursor, said in the discussion thread two weeks ago that a temporary fix has been rolled out and a more permanent solution is planned. "MSFT has a handful of extensions which are closed-source," he wrote, pointing to Remote Access, Pylance, C/C++, and C#. "The latest releases of the specific extensions no longer work in Cursor or other non...