Thanks for the suggestion.
I didn’t rename the file, but to be certain I downloaded the backup again, repeat the restore process, and get the exact same errors as before, so it’s definitely not a file name issue.
I was also able to restore the exact same file (matching md5sum) on a non-Arch image…
Checking inside lib/backup_restore/restorer.rb → def get_dumped_by_version I see:
File.extname(@dump_filename) == '.gz' ? 'zgrep' : 'grep',
On Arch, we have:
zgrep --version
zgrep (gzip) 1.9
And on Ubuntu we have:
zgrep --version
zgrep (gzip) 1.6
It turns out there’s an update in zgrep 1.9…
zgrep -m1 mysite-net-2018-10-28-065449-v20180828065005.tar.gz -e '-- Dumped by pg_dump version
'
gzip: -e.gz: No such file or directory
gzip: -- Dumped by pg_dump version.gz: No such file or directory
% echo $?
2
Vs zgrep 1.6:
zgrep -m1 mysite-net-2018-10-28-065449-v20180828065005.tar.gz -e '-- Dumped by pg_dump version'
ryan@rybuntuvm:~/discourse/public/backups/default$ echo $?
1