The third declaration of the app's identity, and the one #159 did not
cash out in: PKG defaulted to "app.yellowjacket" while
`make android-install` installs whatever is in bin/, which after
`wails3 task android:assemble:apk` is app.yellowjacket.dev. So
android-launch, android-logs and android-smoke addressed a package the
build had not produced, and the certificate-change message named the
wrong id to uninstall -- the release one.
It is derived from bin/yellowjacket.apk the same way the tasks are, so
it follows whichever variant was built last. YJ_ANDROID_PKG still
overrides, and the literal survives only for a tree with no APK yet,
where these commands are asking about whatever is already installed and
there is nothing to read.
cmd_inspect's probe order goes with it: "$PKG.dev" would append a
second suffix to an id that already carries one, so the candidates are
derived from the resolved id in either direction -- debug sibling
first, release second, as before.
The device tier could only take a screenshot and read what Go chose to
log, and a screenshot cannot tell a dropped CSS declaration from a
missing asset. This adds the third thing: the page's own answer, from
the engine that is really rendering it.
`make android-screenshot` grabs the screen, `make android-inspect`
forwards the WebView's devtools socket, and `make android-eval EXPR=...`
evaluates in the real page.
Four details are load-bearing. Only a `debuggable` build opens that
socket, so the debug build type takes `applicationIdSuffix ".dev"` and
installs *beside* the release app -- the two carry different signing
certificates, and Android's only remedy for a changed certificate is an
uninstall, which takes the user's library with it. Playwright cannot
drive a WebView (`connectOverCDP` calls `Browser.setDownloadBehavior`,
which it answers "Browser context management is not supported"), so the
eval is raw CDP over Node's built-in WebSocket. The socket name carries
the pid, so it is resolved per launch rather than written down. And
`exec-out`, not `shell`, for the screenshot: a pty translates LF and
corrupts the PNG.
What it immediately established is why it was worth having. The phone
renders in Chrome 113 at 424x439 CSS px -- two years behind every
browser the other tiers use, with no Popover API and no relaxed CSS
nesting -- so a spec passing at that viewport says nothing about the
device, and two conclusions drawn from version numbers alone were wrong.
Both are corrected in NOTES.md and the plan.
Two bugs, and the first had made every make android-* target dead since
the commit that introduced it.
**The script did not parse at all.** A case pattern read
`*signatures do not match*)`, and `do` is a reserved word: bash rejects
the *whole file*, so android-emulator, android-install, android-smoke
and android-logs all died with "line 190: syntax error near unexpected
token `do'" -- a message that points at a line nobody had reason to
suspect, in a file that had been working. Quoting the inner words fixes
it. A shell script only ever run by hand can carry a syntax error
indefinitely; nothing in the pre-commit hooks runs bash -n.
**A bare adb addresses whatever is attached.** With a second emulator
present -- another project's, or this one's own corpse left `offline` by
a previous run -- every adb call fails with "more than one device", and
cmd_install reported that as "no device - run 'make android-emulator'
first" *directly after* that had printed "waiting for boot ok". Which
is the harness's own house rule broken: a failure that names the wrong
cause is worse than one that names none.
pick_device resolves ANDROID_SERIAL from ro.boot.qemu.avd_name before
any device command. The AVD name is the identity because serials are
assigned in boot order and change between runs; a caller's own
ANDROID_SERIAL wins, and a single device that is not ours is taken as
the target, since that is a phone and a phone is what this tier
actually wants. Verified with both emulators running.
Two harness bugs and the finding that exposed them.
**`pidof` exits 1 when it finds nothing**, and under `set -e` a failing
command substitution killed the script before it could print anything
-- rc=1, no output. That was invisible for as long as the app
crash-*looped*, because there is always some pid in that state. It
appeared the moment the app died for good and ActivityManager stopped
respawning it, which is precisely the run you most want output from.
**And an install failure said nothing useful.** Both ways it fails are
about identity rather than the build: INSTALL_FAILED_VERSION_DOWNGRADE
when a bare `make android` (versionCode 1) meets something a versioned
build left behind, and a signature mismatch when a debug-signed local
build meets a release-signed one. Both were hit in one session, and
both are fixed by uninstalling. The target says so now instead of
leaving someone to read the constant name.
The finding: with the startup bug fixed the app reaches the database
and takes SIGSYS on the x86_64 emulator, because modernc.org/libc's
Xlstat64 issues a raw lstat syscall on linux/amd64 and Android's
seccomp filter forbids it -- bionic never issues it. arm64 has no lstat
syscall at all, so ccgo_linux_arm64.go routes Xlstat through fstatat
and is structurally unaffected; Go's own syscall package already used
fstatat on both.
So the default emulator cannot verify this app, and the skill says so
rather than letting the next session read a tombstone as a regression.
The APK installs and launches. It also dies six milliseconds later, and
finding that out cost a cycle for three reasons that have nothing to do
with the bug itself:
**Go's stdout does not reach logcat.** An Android app's fd 1 and 2 go
to /dev/null, so every slog line -- including the one naming the error
the app is about to exit on -- is discarded. `setprop
log.redirect-stdio true` does not help: that redirects the Java
runtime's System.out, and our code is a c-shared native library.
**os.Exit leaves no evidence.** No panic, no AndroidRuntime stack,
nothing in /data/tombstones, nothing in `logcat -b crash` or dropbox.
All three places anyone would look are empty, and the one signal that
is present -- "Zygote: exited due to signal 9" -- reads as "the system
killed it" and sends you after the low-memory killer.
**ActivityManager restarts it faster than you can observe.** pidof
always answers and `am start` always reports Status: ok, so a
crash-looping app looks alive. "Did it start" is the wrong question;
`make android-smoke` asks whether it is the *same pid* N seconds later,
and prints the filtered logcat plus how to read it when it is not.
The tell, once known: "I/WailsBridge: Wails bridge initialized"
followed immediately by a new pid doing the same thing.
scripts/android-emulator.sh follows dev-headless.sh's shape --
background start, saved-PID stop, filtered log tail, never pkill -f.
Two scaffold tasks are deliberately not wrapped: `android:logs` greps
logcat for (Wails|yellowjacket), which catches the WailsBridge tag but
misses the app's own process tag (app.yellowjacket is lowercase) and
misses ActivityManager's "has died" line, which is the one that says it
crashed; and `ensure-emulator` boots whatever `-list-avds | tail -1`
returns, with no pidfile and no boot wait, so it cannot be sequenced.
One environment note that is not obvious on Arch: Gradle needs a
platform and /opt/android-sdk has none, so ANDROID_SDK defaults to
~/Android/Sdk while ANDROID_NDK points at /opt/android-ndk. Two SDKs,
one for each half of the build.
logan