scaleway/compute-instance v2.3.1
ADR-0102's cockpit wiring (v2.3.0) writes /etc/alloy/config.alloy via cloud-init write_files before runcmd installs the alloy package. The alloy .deb also ships /etc/alloy/config.alloy as a conffile, so dpkg detects the pre-existing file and tries to prompt interactively asking whether to keep it or take the package's default. cloud-init's runcmd script has no attached stdin, so dpkg hits EOF on the prompt and aborts configuring the package — alloy.service is left half-installed and fails to start (Result: resources), confirmed live against a real applied test-bed instance (cloud-init status --long showed Runparts: 1 failures (runcmd), and /var/log/cloud-init-output.log showed the exact *** config.alloy (Y/I/N/O/D/Z) prompt followed by end of file on stdin at conffile prompt).
Fix: pass dpkg's --force-confold option (keep the already-present file, don't prompt) to the alloy install, plus DEBIAN_FRONTEND=noninteractive for good measure. This is exactly the outcome we want, since the whole point of pre-writing the file was to have our rendered config win over the package's default.
Patch release — no input/output/behavior change beyond fixing a previously-broken case.