bug#81502: 回复: 回复: Re: bug#81502: [PATCH] tests: chgrp: test --preserve-root within a chroot env

   5. A quick summary of what extra this tests： We use a chroot
   environment for the --no-preserve-root test to avoid any risk.
   主   题：回复: Re: bug#81502: [PATCH] tests: chgrp: test --preserve-root
   within a chroot env
   日   期：2026年07月29日18:28
   发件人：左洪盛
   收件人：81502,Pádraig Brady,左洪盛

   Thank you for your comments. Here are my responses:

   1. Regarding running as root:   my plan is indeed to run `chgrp` as
   root inside the chroot. Since the chroot environment isolates all
   operations to a temporary test directory, I believe it is safe. I
   considered `chroot --userspec=...`, but given that the entire
   filesystem is under our control, the root‑inside‑chroot approach should
   be acceptable.

   2. About testing both `chown` and `chgrp`:     I agree they are
   essentially the same. However, several coreutils commands support
   `--preserve-root` and `--no-preserve-root`, and in theory they all need
   testing. I think having separate tests for each command makes the
   coverage clearer and easier to maintain.

   3. On the use of `command -v` and `cp --parents`:    the source binary
   we copy is the one built during the current compilation (from `src/`),
   so we don't need to use `command -v` to locate it. The current approach
   directly uses that built binary.

   4. For the `|| true` question:     you're right – most of them are
   redundant. I have removed them in the updated patch. Please find the
   revised patch attached, which includes the removal of these unnecessary
   constructs.

   Let me know if you have any further questions.

   Note: I am not a native English speaker; the content above was
   translated with the help of AI, and  I fully understad those. Thank you
   for your understanding.

   Thanks,
   Zuo Hongsheng

   主   题：Re: bug#81502: [PATCH] tests: chgrp: test --preserve-root within
   a chroot env
   日   期：2026年07月27日19:12
   发件人：Pádraig Brady
   收件人：81502,Pádraig Brady
   On 27/07/2026 04:03, zuohsh wrote: > * tests/local.mk: reference the
   new test. > * tests/chgrp/preserve-root.sh: the new file. > --- >
   +print_ver_ chgrp > +require_root_ OK so you're proposing this as root
   to support chroot, rather than have chgrp operate as root? In that case
   I think chroot --userspec=... would be safer. Also a general point is
   that chown and chgrp are essentially the same, so it would be good to
   test both. Actually we already have an existing
   https://github.com/coreutils/coreutils/blob/master/tests/chown/preserve
   -root.sh so it would be good to mention a quick summary of what extra
   this tests. > + > +# Create a safe chroot environment for testing >
   +chroot_dir="$PWD/chroot_test" > +mkdir -p
   "$chroot_dir"/{bin,lib,lib64,etc,dev,tmp} || framework_failure_ > +#
   Copy essential files for chroot to work > +cp /bin/sh
   "$chroot_dir/bin/" 2>/dev/null || \ > + cp /usr/bin/sh
   "$chroot_dir/bin/sh" 2>/dev/null || framework_failure_ > + > +# Copy
   required libraries if any > +ldd $chroot_dir/bin/sh 2>/dev/null | grep
   -o '/lib[^ ]*' | while read lib; do > + test -f "$lib" && cp "$lib"
   "$chroot_dir/lib/" 2>/dev/null || true > +done > + > +pwd > +# Copy
   chgrp binary to chroot > +cp ${srcdir}/src/chgrp
   "$chroot_dir/bin/chgrp" || framework_failure_ > + > +# Copy chgrp's
   required libraries > +ldd $chroot_dir/bin/chgrp | grep -o '/lib[^ ]*' |
   while read lib; do > + test -f "$lib" && cp "$lib" "$chroot_dir/lib/"
   2>/dev/null || true > + test -f "$lib" && cp "$lib"
   "$chroot_dir/lib64/" 2>/dev/null || true > +done Note the chroot setup
   we use in
   https://github.com/coreutils/coreutils/blob/master/tests/nproc/nproc-qu
   ota.sh where we use `command -v ...` to identify the binary, and cp
   --parents to copy the dependencies. > + > +# Create minimal device
   nodes > +mknod "$chroot_dir/dev/null" c 1 3 2>/dev/null || true >
   +chmod 666 "$chroot_dir/dev/null" 2>/dev/null || true Why the || true
   here? > + > +# Test 1: --preserve-root should refuse recursive
   operation on / > +echo "=== Test 1: preserve-root on / ===" >&2 >
   +chroot "$chroot_dir" /bin/chgrp -R --preserve-root 1 / 2>out && fail=1
   > +echo "=== Test 1 output ===" >&2 > +cat out >&2 > +echo "=== End
   Test 1 output ===" >&2 > +grep "it is dangerous to operate
   recursively.*'/'" out >/dev/null || fail=1 > + > +# Test 2:
   --no-preserve-root should allow the operation > +chroot "$chroot_dir"
   /bin/chgrp -R --no-preserve-root 1 / 2>out || true and here? thanks,
   Padraig




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