Surface Google Play download errors and exit non-zero on failure

[minner-fun]

The problem

Every error message in the Google Play download path is silently discarded whenever apkeep runs without a TTY on stderr — piped, redirected, or under CI, cron, or Docker without -t. The process also exits 0 regardless, so a caller cannot detect the failure at all.

Reproducing, before this change:

$ apkeep -a com.mojang.minecraftpe -d google-play -e ... -t ... ./out 2>&1
Downloading com.mojang.minecraftpe...
$ echo $?
0

No error, no file, no non-zero exit. The same happens for a nonexistent package, a permission error, or three exhausted retries.

Why it happens

MultiProgress::println() writes through indicatif's draw target. ProgressDrawTarget::term() returns Self::hidden() when stderr is not a color-capable terminal, and a hidden target makes width() return None, which makes draw() return Ok(()) before emitting anything. The message is dropped, and because the result is Ok, the .unwrap() at each call site does not panic either.

The two success messages were unaffected only because they go through suspend(), which is documented to run its closure even when the draw target is hidden. Every one of the seven error messages used println().

The change

• Route the error messages through suspend() + eprintln!. They now survive in non-interactive contexts and stay on stderr, which is where the draw target had been sending them all along.
• Propagate a failure count out of download_apps() and exit non-zero when it is greater than zero. An already-present file counts as success; unavailable apps, permission errors, exhausted retries, and version-pinned requests count as failures.
• Reword the InvalidApp message. The API returns that same error kind for several conditions that are indistinguishable in the response, so naming just one of them is misleading.

After

Case	Before	After
Paid / unavailable app	silent, exit 0	message, exit 1
Nonexistent package	silent, exit 0	message, exit 1
File already exists	silent, exit 0	message, exit 0
Version pinned (app@1.2.3)	silent, exit 0	message, exit 1
Successful download	works	works, exit 0

Testing

Built with cargo build --release (no new warnings) and ran each row of the table above against a live Google Play account. Also confirmed that 2>/dev/null leaves only the Downloading ... line on stdout, so the stdout/stderr split is intact, and that the progress bars still render normally in a terminal.

The same println() pattern exists in the APKPure, F-Droid, and Huawei App Gallery sources. This PR deliberately leaves those alone to stay reviewable; happy to follow up with the same treatment if you would like it in a separate change.

🤖 Generated with Claude Code