This bug has to do with the frag deflator thread in mksquashfs. I haven't fully determined the problem but it is likely due to parallel processing (NOTE: the '-processors 1' option does not solve the bug). There's an out-of-tree patch that disables the thread by removing its working queue:
https://github.com/intrigeri/squashfs- tools/commit/c2c4d15580adee66b68c29eb9d2ee660225449bc I've verified that the patch results in consistent, reproducible squashfs images: $ md5sum *.snap 0161f2c324cb2753429b8c51818132c5 nmap_1.snap 0161f2c324cb2753429b8c51818132c5 nmap_2.snap 0161f2c324cb2753429b8c51818132c5 nmap_3.snap 0161f2c324cb2753429b8c51818132c5 nmap_4.snap 0161f2c324cb2753429b8c51818132c5 nmap_5.snap 5fccb0276e2cd329021591129855eb83 nmap_7.12SVN-0.4_armhf.snap Note that nmap_7.12SVN-0.4_armhf.snap is the snap that was originally attached to this bug which was created with a mksquashfs that had the frag deflator thread enabled, so its snap differs from the ones created with the patched mksquashfs. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1576763 Title: pi2 images generate different checksums on repeated runs To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/click-reviewers-tools/+bug/1576763/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
