Okay, so I need to classify this bug report about QEMU as either user-mode or system-mode related. Let me think through this step by step. First, the problem is a build failure when installing QEMU 5.2.0 and 6.0.0 using Homebrew on macOS. The error mentioned is conflicts with the C++20 version header. Hmm, that sounds like it's an issue during compilation or linking, possibly related to dependencies or system libraries. QEMU itself can run in both user-mode and system-mode emulation. User-mode emulates a CPU in a process, while system-mode emulates the entire machine, including hardware devices. But this bug is about building QEMU, not running it. When installing software via Homebrew, especially with formulas that build from source, you often encounter issues related to dependencies or compiler versions. The C++20 header conflict suggests that either the system's headers are conflicting with those expected by the QEMU build, or perhaps the toolchain isn't properly set up for C++20. I remember that when installing software that requires specific compiler versions or libraries, it can sometimes interfere with existing system installations. Since this is a build issue, it might involve system-wide headers and libraries, which are typically managed at a lower level than user applications. Moreover, QEMU, being an emulator, interacts deeply with the host system, including device drivers and kernel interfaces when running in system-mode. But since the problem occurs during installation, it's more about the build environment than runtime operations. So, considering that this is a build issue involving system headers and compiler versions, it likely falls under system-mode because it relates to the underlying system setup needed to compile QEMU correctly. If it were just a user application issue, maybe it would be different, but since it's about building with specific system tools, I think it's system-mode related. system