Ran export -> uninstall -> import on trivy against the live install. It
worked end to end (1.3G app, marker file byte-identical afterwards,
container running, database status correct, tree owned by the container
user) but only after three real bugs, none of which syntax checks or
isolated tests would have caught.
Export wrote the tarball as the CONTAINER user, because tar has to read
app data holding sub-UIDs the manager cannot. That meant the container
user also had to be able to create the destination file, which fails for
any normal destination. Now tar writes to stdout and the caller's shell
creates the file: reading uses the privileges that need it, writing uses
the caller's. Import had the mirror-image bug — tar extracted as the
container user and so could not READ a manager-owned .lpapp; the caller
now opens it and tar reads stdin.
Export also failed at tar time with no hint that the destination was the
problem, so it checks the directory exists and is writable up front.
The third one was quiet and worse. The manifest is pretty-printed, so it
reads `"size_bytes": 1324973614` — with a space that a `"key":[0-9]*`
pattern does not match. Both size_bytes and storage.location came back
empty everywhere they were read, which turned "will it fit" and "does
that location still exist" into checks that always passed. That is the
failure mode preflight exists to prevent, hiding inside preflight itself.
Fixed in app_portable.sh and restore_preflight.sh.
Verified afterwards with crafted manifests: an app claiming 8 TB is now
refused on an 800 GB disk ("Needs 8192G, 806G free"), and one naming a
location this machine lacks warns and names the fallback.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>