sudo-rs — the default sudo from Ubuntu 25.10, so on 26.04 — does not
implement bare -E. It does not reject it either: it warns to stderr
("preserving the entire environment is not supported, '-E' is ignored")
and runs the command with the environment DROPPED, leaving the exit
status untouched. Callers capture stderr, so the warning is invisible and
the backup engines simply never receive RESTIC_PASSWORD / BORG_PASSPHRASE
/ KOPIA_PASSWORD and cannot open the repository.
Name the nine vars explicitly via --preserve-env=<list>, which sudo-rs
and classic sudo (>=1.8.21, so Debian 10's 1.8.27) both honour, so this
needs no version gate. The list is cross-checked against every
RESTIC_/BORG_/KOPIA_ var the engine env scripts export.
The list lives in variables.sh with a literal fallback in runBackupOp,
because init.sh sources run_privileged.sh directly during install without
ever loading variables.sh — an unguarded empty list would silently
reproduce the same dropped-credential bug.
restoreFirstRunDiscover now goes through runBackupOp rather than issuing
its own sudo. It was the only backup-engine call bypassing that funnel,
which is why it missed this fix by construction; routing it back also
gives it the -H that keeps restic's cache under the backup user's HOME.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
48cb5d9380