QEMU doesn't build reproducibly anymore in 5.2.0

[Apteryx]

It used to be that building QEMU 5.1.0 twice in a row, using Guix, would result in bit-for-bit identical results.

Starting with 5.2.0, this is no longer true. Here's a summary of which files have non-determinism:

Here's a summary of the differing files:

$ diff -r /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0{,-check}
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-aarch64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-aarch64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-aarch64_be and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-aarch64_be differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-alpha and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-alpha differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-arm and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-arm differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-armeb and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-armeb differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-cris and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-cris differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-edid and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-edid differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-ga and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-ga differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-hppa and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-hppa differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-i386 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-i386 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-img and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-img differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-io and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-io differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-keymap and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-keymap differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-m68k and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-m68k differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-microblaze and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-microblaze differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-microblazeel and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-microblazeel differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-mips and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-mips differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-mips64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-mips64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-mips64el and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-mips64el differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-mipsel and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-mipsel differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-mipsn32 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-mipsn32 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-mipsn32el and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-mipsn32el differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-nbd and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-nbd differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-nios2 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-nios2 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-or1k and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-or1k differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-ppc and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-ppc differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-ppc64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-ppc64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-ppc64le and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-ppc64le differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-pr-helper and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-pr-helper differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-riscv32 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-riscv32 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-riscv64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-riscv64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-s390x and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-s390x differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-sh4 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-sh4 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-sh4eb and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-sh4eb differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-sparc and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-sparc differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-sparc32plus and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-sparc32plus differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-sparc64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-sparc64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-storage-daemon and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-storage-daemon differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-aarch64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-aarch64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-alpha and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-alpha differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-arm and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-arm differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-avr and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-avr differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-cris and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-cris differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-hppa and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-hppa differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-i386 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-i386 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-m68k and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-m68k differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-microblaze and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-microblaze differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-microblazeel and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-microblazeel differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-mips and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-mips differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-mips64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-mips64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-mips64el and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-mips64el differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-mipsel and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-mipsel differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-moxie and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-moxie differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-nios2 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-nios2 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-or1k and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-or1k differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-ppc and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-ppc differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-ppc64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-ppc64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-riscv32 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-riscv32 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-riscv64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-riscv64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-rx and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-rx differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-s390x and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-s390x differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-sh4 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-sh4 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-sh4eb and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-sh4eb differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-sparc and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-sparc differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-sparc64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-sparc64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-tricore and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-tricore differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-x86_64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-x86_64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-xtensa and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-xtensa differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-system-xtensaeb and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-system-xtensaeb differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-x86_64 and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-x86_64 differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-xtensa and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-xtensa differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/bin/qemu-xtensaeb and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/bin/qemu-xtensaeb differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/libexec/qemu-bridge-helper and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/libexec/qemu-bridge-helper differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/libexec/vhost-user-gpu and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/libexec/vhost-user-gpu differ
Binary files /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0/libexec/virtiofsd and /gnu/store/l286mbanw78qgbn54gs5j23qm0v9abhw-qemu-5.2.0-check/libexec/virtiofsd differ

Attached is a sample log of diffoscope for the qemu-aarch64 binary.

[Apteryx (maxco)]

Hello, this problem is resolved when using Meson 0.57.1, as suggested by bonzini on #qemu (OFTC).

[Thomas Huth (th-huth)]

Ok, thanks for the update, so I'm closing this ticket now.