semantic: 0.167 other: 0.139 graphic: 0.115 device: 0.106 files: 0.064 PID: 0.063 vnc: 0.058 boot: 0.055 permissions: 0.051 network: 0.045 performance: 0.042 debug: 0.041 socket: 0.039 KVM: 0.014 debug: 0.240 files: 0.164 other: 0.152 network: 0.085 performance: 0.082 PID: 0.057 device: 0.046 semantic: 0.042 socket: 0.032 boot: 0.026 KVM: 0.020 permissions: 0.020 graphic: 0.019 vnc: 0.018 qemu-user fails to run rpcgen (i386, x86_64) Confirmed on qemu current development tree (git commit aa29141). While trying to run eglibc's rpcgen from native system by qemu-user, I get an error: qemu-x86_64 /usr/bin/rpcgen -c /dev/null fork: Invalid argument I am running a Debian Wheezy system and rpcgen comes from libc-dev-bin. Just in case I am attaching my rpcgen binaries from i386 and x86_64 systems. Very similar problem was mentioned on the QEMU forum on February 2007, so I guess it might be a known issue. Nevertheless, I was unable to find any information about bug reports, fixes nor workarounds for it so I'm reporting it here. This should be fixed in QEMU 1.6.