Author: Conan Technical Documentation Team Publication Date: April 2026 Category: Software Engineering / Package Management Abstract Conan, the decentralized C/C++ package manager, relies heavily on a local cache directory known as the Conan home ( CONAN_HOME ). However, in certain constrained or legacy environments, the conan_user_home environment variable provides a legacy fallback mechanism to determine the user's home directory when the standard CONAN_HOME is not explicitly defined. This paper clarifies the role, precedence, and proper application of conan_user_home , distinguishing it from CONAN_HOME and native operating system home variables. We provide technical guidelines for developers and CI/CD engineers to avoid configuration pitfalls and ensure reproducible builds. 1. Introduction Conan 1.x and early 2.x releases introduced several environment variables to customize runtime behavior. Among them, conan_user_home was designed as an override for the underlying system’s concept of the user home directory (e.g., $HOME on Linux/macOS, %USERPROFILE% on Windows). The variable allows users to redirect Conan’s default cache location without modifying the broader system’s home path.