tracker: tar 1.34 replace barfs: Skipping to next header

[edsantiago]

Copy-paste and save as test-tar:

#!/bin/bash

set -ex

IMG=${1?Missing IMAGE arg}

tmpdir=$(mktemp -d --tmpdir test-tar.XXXXXXX)

echo cd $tmpdir
cd $tmpdir

touch file1
echo "modified" >file2

cat >Containerfile <<EOF
FROM $IMG
ADD file1 /tmp
WORKDIR /tmp
EOF

podman rmi -f testimage

podman build -t testimage .
podman create --name testctr testimage
podman export -o ctr.tar testctr
podman rm testctr

tar --delete -f ctr.tar tmp/file1
tar -rf ctr.tar file2

With tar-1.34-8.fc38.x86_64:

• Run script with quay.io/libpod/testimage:20221018. It passes.
• Run script with quay.io/libpod/testimage:20240123. It fails:

...
+ tar --delete -f ctr.tar tmp/file1
+ tar -rf ctr.tar file2
tar: Skipping to next header
tar: Exiting with failure status due to previous errors
# echo $?
2

Works perfectly fine with tar-1.35-2.fc39.x86_64. The question is, was this an intentional bug fix in 1.35, or is it just luck that it works in 1.35 and we will see this again?

Filing under podman because I need a holding place somewhere.

[giuseppe]

yes, this is indeed a GNU tar bug that is fixed in the 1.35 release.

I've bisected GNU tar and can confirm the following patch fixes the issue with --delete: https://git.savannah.gnu.org/cgit/tar.git/commit/?id=f8e14746d2ca72804a4520c059d7bf65ca00c5ac

[edsantiago]

Thank you @giuseppe!