Okay, let me try to figure out how to classify this bug report. The user is talking about an issue with qemu-i386-static where it's failing to reserve a certain amount of virtual address space. The error message mentions "Operation not supported" when using the MAP_FIXED_NOREPLACE flag in the mmap syscall. Looking at the strace output, the mmap call is returning EOPNOTSUPP. The problem seems to be that the kernel (version 4.4) doesn't support MAP_FIXED_NOREPLACE, but QEMU is trying to use it anyway. The user explains that QEMU checks for this feature at build time using #ifndef, but that's not effective here because the actual support is at runtime. The key point here is that the issue arises because QEMU isn't checking at runtime whether the kernel supports MAP_FIXED_NOREPLACE. Instead, it's relying on build-time checks, which might not account for the actual runtime environment. The error occurs during execution (runtime) when the mmap syscall is made with an unsupported flag. So, the problem isn't a faulty instruction (which would be assembly or machine code related), nor is it a syscall error in the sense of incorrect parameters (though the syscall is made with an unsupported flag). The main issue is that the runtime environment (the kernel) doesn't support a feature that QEMU assumes is available based on build-time checks. Therefore, this is a runtime error because it's about the program's behavior during execution depending on the environment. runtime