[joshuatam]

Problem

android/package-gamescope.sh absorbed the Xwayland payload behind an existence check:

[ -x "$XW_DIR/build-android/hw/xwayland/Xwayland" ] || bash "$XW_DIR/android/build-xwayland.sh"

So the binary was built only when it was missing. The daemon libraries staged a few dozen lines above it get a strict check_fresh guard against the sources they compile, but Xwayland got nothing: once a binary existed, any change to gamenative-xwayland source — hw/xwayland, Xext, the glamor/GBM path — packaged the previous build silently and the asset shipped a stale Xwayland.

That is not hypothetical. The tree this was written on was in exactly that state: Xext/shm.c and hw/xwayland/xwayland-glamor-gbm.c were newer than the 2026-10-22 Xwayland binary, and the old predicate would have copied that binary into the payload without a word. On device it presents as a missing or wrong behaviour in the X server behind gamescope — an X extension the guest expects, a glamor/GBM fix that simply is not there — with nothing in the build log pointing at the binary.

Fix

Build it always, the way the daemon libraries above are built, and assert the result converged:

bash "$XW_DIR/android/build-xwayland.sh"
if ! ninja -C "$XW_DIR/build-android" -n 2>/dev/null | grep -qx 'ninja: no work to do.'; then
    echo "error: $XW_BIN is not current after build-xwayland.sh — ninja still has work" >&2
    exit 1
fi

build-xwayland.sh is incremental (meson reconfigure, ninja relinks only what changed), so a current tree pays only its xkbcomp/xkeyboard-config tail; a stale tree pays a rebuild, which is the point. If the dry run still reports work, the script fails naming the binary rather than packaging it.

Why ninja's dry run and not a check_fresh source scan

A find -newer scan cannot answer this question for this tree: the xkbcomp tail rewrites android/deps/xkbcomp-build/config.h after the link, so "any source newer than the binary" is true on every run and the check would fail the build permanently. ninja already knows every input, including that generated header, so ninja: no work to do. is the honest statement that the binary matches its sources.

Measurement

On a current tree the always-rebuild costs 8.9–9.5 s over three warm runs, and the dry run settles at ninja: no work to do.

Touch nothing else: this is one file, and the patch train's dirty src/ tree is not part of the commit.