From 380206dcfc2be30751db3faec4396f7f8882a8ae Mon Sep 17 00:00:00 2001
From: Istvan Matejcsok <119620946+matejcsok-ee@users.noreply.github.com>
Date: Thu, 11 Jun 2026 13:23:23 +0200
Subject: [PATCH] fix(build): host postprocess silently no-ops when emsdk tools
 are stubbed
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build-kicad-target.sh swaps emsdk's wasm-opt/wasm-emscripten-finalize for
no-op stubs (real binaries preserved as *.real) so emcc skips in-link
asyncify — intended for the CONTAINER emsdk, but a host-mode run left the
host tools/emsdk stubbed (since Jun 9). The stub fakes --version and exits 0,
so every local build's host-side finalize/asyncify/-O2 "succeeded" while
doing nothing: output wasm shipped non-asyncified and aborts at boot with
"asyncify_stop_unwind is not a function" (and stayed 122M vs the correct
187M). get-wasm-opt.sh and apply-finalize.sh now prefer the *.real binary
whenever it exists, making the resolution immune to a stubbed emsdk.

Found while validating the CI e2e fix: pcbnew.wasm built this morning could
not boot in any browser. Local artifacts built since Jun 9 may need their
postprocess re-run (apply-finalize.sh + apply-asyncify.sh).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 scripts/common/apply-finalize.sh | 6 ++++++
 scripts/common/get-wasm-opt.sh   | 9 +++++++++
 2 files changed, 15 insertions(+)

diff --git a/scripts/common/apply-finalize.sh b/scripts/common/apply-finalize.sh
index 1f778c5..d4e8585 100755
--- a/scripts/common/apply-finalize.sh
+++ b/scripts/common/apply-finalize.sh
@@ -13,6 +13,12 @@ PROJECT_ROOT="$(cd "${SCRIPT_DIR}/../.." && pwd)"
 WASM_OPT=$("${SCRIPT_DIR}/get-wasm-opt.sh")
 BINARYEN_BIN=$(dirname "${WASM_OPT}")
 FINALIZE="${BINARYEN_BIN}/wasm-emscripten-finalize"
+# Same stub hazard as wasm-opt (see get-wasm-opt.sh): a host-mode kicad build
+# leaves the emsdk finalize stubbed with the real binary at .real — prefer it,
+# the stub exits 0 having done nothing.
+if [ -x "${FINALIZE}.real" ]; then
+    FINALIZE="${FINALIZE}.real"
+fi
 
 INPUT_WASM="${1:-output/pcbnew.wasm}"
 OUTPUT_WASM="${2:-${INPUT_WASM}}"
diff --git a/scripts/common/get-wasm-opt.sh b/scripts/common/get-wasm-opt.sh
index 1e9e9f7..6b33b3a 100755
--- a/scripts/common/get-wasm-opt.sh
+++ b/scripts/common/get-wasm-opt.sh
@@ -25,6 +25,15 @@ PROJECT_ROOT="$(cd "${SCRIPT_DIR}/../.." && pwd)"
 # v130 (see docs/ci-build-slowness-findings.md). Validate any bump with the e2e
 # suite: a Binaryen/emsdk skew can corrupt asyncify metadata ("func is not a function").
 EMSDK_WASM_OPT="${PROJECT_ROOT}/tools/emsdk/upstream/bin/wasm-opt"
+# build-kicad-target.sh replaces emsdk's wasm-opt with a no-op stub (moving the
+# real binary to wasm-opt.real) so emcc skips the in-link asyncify. That's meant
+# for the container emsdk, but a host-mode run leaves the HOST emsdk stubbed —
+# and the stub fakes --version and exits 0, so the host-side asyncify/-O2
+# "succeed" while doing NOTHING (broken wasm: "asyncify_stop_unwind is not a
+# function"). Always prefer the preserved real binary when it exists.
+if [ -x "${EMSDK_WASM_OPT}.real" ]; then
+    EMSDK_WASM_OPT="${EMSDK_WASM_OPT}.real"
+fi
 if [ -z "${BINARYEN_VERSION:-}" ] && [ -x "${EMSDK_WASM_OPT}" ]; then
     EMSDK_VERSION=$("${EMSDK_WASM_OPT}" --version 2>&1 || true)
     echo "Using emsdk-bundled Binaryen: ${EMSDK_VERSION}" >&2