Public bug reported: Rsync in Ubuntu 20.10 fails when /proc isn't mounted, while it worked before. This happens because AC_CHECK_FUNC(lchmod) returns "yes" in 20.10, while it returned "no" before.
Steps to reproduce: # Emulate /proc not being mounted $ mount --bind / /mnt $ chroot /mnt rsync -a /bin/ls . rsync: [receiver] failed to set permissions on "/.ls.CDExhu": Operation not supported (95) rsync error: some files/attrs were not transferred (see previous errors) (code 3) at main.c(1330) [sender=3.2.3] I reported this issue upstream in https://github.com/WayneD/rsync/issues/109 but the rsync developer says it's a problem in libc, and it might well be. Simple C code to reproduce the problem without rsync: printf("lchmod returned: %d\n", lchmod("/tmp/ls", 0755)); If /tmp/ls is e.g. mode=0123, and needs to be changed, lchmod fails when /proc isn't mounted, yet it succeeds if it is mounted. Python had a similar issue, and they ended up avoiding AC_CHECK_FUNC(lchmod) under Linux: https://bugs.python.org/issue34652 https://github.com/python/cpython/commit/69e96910153219b0b15a18323b917bd74336d229#diff-49473dca262eeab3b4a43002adb08b4db31020d190caaad1594b47f1d5daa810R3140 ```c if test "$MACHDEP" != linux; then AC_CHECK_FUNC(lchmod) fi ``` So I'm not sure which package is causing the bug here. Should autoconf return false? Should libc implement lchown without the bug? Or should rsync skip lchmod under Linux, like python did? ** Affects: rsync (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1902109 Title: rsync uses lchmod and fails in Ubuntu >= 20.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/rsync/+bug/1902109/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
