Hi, Quoting Julien Puydt (2024-12-05 17:17:14) > I updated my chroot two hours ago ; then I couldn't use it anymore, so I > tried to update it again : > > $ sbuild-update --chroot-mode=unshare --update --dist-upgrade -- > autoremove -d unstable > Use of uninitialized value $dist in pattern match (m//) at > /usr/share/perl5/Sbuild/ChrootUnshare.pm line 168. > Use of uninitialized value $dist in pattern match (m//) at > /usr/share/perl5/Sbuild/ChrootUnshare.pm line 168. > Use of uninitialized value $dist in concatenation (.) or string at > /usr/share/perl5/Sbuild/ChrootUnshare.pm line 188. > I: Unpacking /home/jpuydt/.cache/sbuild/unstable-amd64.tar.zst to > /tmp/tmp.sbuild.PlufuvF3vB... > zstd: /*stdin*\: unsupported format > tar: Child returned status 1 > tar: Error is not recoverable: exiting now > bad exit status (2): /usr/libexec/sbuild-usernsexec u:0:100000:65536 > g:0:100000:65536 > -- tar --exclude=./dev/urandom --exclude=./dev/random -- > exclude=./dev/full --exclude=./dev/null --exclude=./dev/console -- > exclude=./dev/zero --exclude=./dev/tty --exclude=./dev/ptmx --directory > /tmp/tmp.sbuild.PlufuvF3vB --extract --zstd > Error setting up unstable chroot > Chroot setup failed at /usr/bin/sbuild-update line 145. > > From the error message, I would say something isn't a valid zstd file > but: > $ file /home/jpuydt/.cache/sbuild/unstable-amd64.tar.zst > /home/jpuydt/.cache/sbuild/unstable-amd64.tar.zst: Zstandard compressed > data (v0.8+), Dictionary ID: None > > > So I'm a bit at loss as to why things are broken.
my hunch is this part of the zstd manual page:
> ○ -f, --force: disable input and output checks. Allows overwriting
> existing files, input from console, output to stdout, operating
> on links, block devices, etc. During decompression and when the
> output destination is stdout, pass-through unrecognized formats
> as-is.
Sbuild does not pass the --force parameter when it passes data to extract to
the zstd utility.
In your /usr/share/perl5/Sbuild/ChrootUnshare.pm, can you try applying this
patch:
--- a/usr/share/perl5/Sbuild/ChrootUnshare.pm
+++ b/usr/share/perl5/Sbuild/ChrootUnshare.pm
@@ -517,7 +517,7 @@ sub begin_session {
} elsif ("\xFD7zXZ" eq substr $chunk, 0, 5) {
@decompress = ('xz', '--decompress', '--stdout');
} elsif ("\x28\xB5\x2F\xFD" eq substr $chunk, 0, 4) {
- @decompress = ('zstd', '--decompress', '--stdout');
+ @decompress = ('zstd', '--decompress', '--stdout', '--force');
} elsif ("\x04\x22\x4d\x18" eq substr $chunk, 0, 4) {
# tar does not seem to support lz4 magic, but we do
@decompress = ('lz4', '--decompress', '--stdout');
Should that be the problem, we could add the --force flag and call it a day.
But as its name implies, the --force flag is doing more things than just allow
reading data from standard input (see above). Why does zstd need --force for
such a task while all other compressors do not? Sounds like a bug?
Thanks!
cheers, josch
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