Package: dpkg Version: 1.23.7 Dear Maintainers,
BACKGROUND I have a cool script that downloads a .deb file using curl, grovels the Version out of the beginning of the file, and aborts the download if it's not a new version. This is useful because Zoom just has a URL zoom_amd64.deb with no version number until you look inside. The script is at https://github.com/barak/zoom-ubuntu-repo/blob/master/zoom-up and the salient bash lines, simplified, are touch tmp/zoom curl https://zoom.us/client/latest/zoom_amd64.deb >> tmp/zoom & ... v=$(dpkg --field <(tail --follow --bytes=+0 tmp/zoom) Version) which gets the new version into $v ASAP so it can be tested and the download aborted as appropriate. This used to work fine, but with a new version of dpkg it gets dpkg-deb: error: archive '/dev/fd/63' is truncated or corrupt, expected more data than available (35724 > 0) ISSUE What's going on is that the new version of dpkg-deb does a seek on its file argument, which fails if it's not a real file. You can see it here: $ dpkg --field /var/cache/apt/archives/task-ssh-server_3.86_all.deb Version 3.86 $ dpkg --field <(cat /var/cache/apt/archives/task-ssh-server_3.86_all.deb) Version dpkg-deb: error: archive '/dev/fd/63' is truncated or corrupt, expected more data than available (608 > 0) $ shasum /var/cache/apt/archives/task-ssh-server_3.86_all.deb 2454b0c8bec4b9f30efc5ef9a28e7dbfc76a3c65 /var/cache/apt/archives/task-ssh-server_3.86_all.deb $ shasum <(cat /var/cache/apt/archives/task-ssh-server_3.86_all.deb) 2454b0c8bec4b9f30efc5ef9a28e7dbfc76a3c65 /dev/fd/63 It would be nice if dpkg-deb would continue to allow a non-seekable argument, so my lazy pipe stream trick would continue to work. Cheers, --Barak.
