Warn on missing decode tools on both toolchains, fail the CI key resolver loudly

The PlatformIO branch of _decode_pc now routes through the same
rate-limited warning as the native one; raw undecoded crash addresses
with no stated reason were undiagnosable at default log level. The CI
cache key uses the assignment form so errexit catches a resolver
failure instead of echo swallowing it into a degenerate key, with a
non-empty check, and the cache comments stop claiming a ccache store
the seed job never populates (it saves before any compile runs).

.github/workflows/ci.yml

@@ -199,7 +199,11 @@ jobs:
         id: esp8266-native-cache-key
         run: |
           . venv/bin/activate
-          echo "key=esp8266-native-$(python -c 'from esphome.components.esp8266 import RECOMMENDED_ARDUINO_FRAMEWORK_VERSION as f; from esphome.arduino8266.framework import TOOLCHAIN_VERSION as t; print(f"{f}-{t}")')" >> $GITHUB_OUTPUT
+          # Assignment form so errexit catches a resolver failure; a nested
+          # $(...) inside echo would silently yield a degenerate key
+          key=$(python -c 'from esphome.components.esp8266 import RECOMMENDED_ARDUINO_FRAMEWORK_VERSION as f; from esphome.arduino8266.framework import TOOLCHAIN_VERSION as t; print(f"{f}-{t}")')
+          [ -n "$key" ] || exit 1
+          echo "key=esp8266-native-$key" >> $GITHUB_OUTPUT
       - name: Cache the native toolchain
         id: esp8266-native-cache
         uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
@@ -1187,7 +1191,8 @@ jobs:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
 
-      # ~110 MB of framework + toolchain plus the ccache store. The versions
+      # ~110 MB of framework + toolchain (no ccache: the seed job saves
+      # before any compile runs, so the store would always be empty). The versions
       # are pinned in code, not in a hashable file, so resolve them for the
       # key (actions/cache never overwrites a key, so a bump must change it).
       # PRs are restore-only; the shared entry is seeded on pushes to dev by
@@ -1196,9 +1201,13 @@ jobs:
         id: esp8266-native-cache-key
         run: |
           . venv/bin/activate
-          echo "key=esp8266-native-$(python -c 'from esphome.components.esp8266 import RECOMMENDED_ARDUINO_FRAMEWORK_VERSION as f; from esphome.arduino8266.framework import TOOLCHAIN_VERSION as t; print(f"{f}-{t}")')" >> $GITHUB_OUTPUT
+          # Assignment form so errexit catches a resolver failure; a nested
+          # $(...) inside echo would silently yield a degenerate key
+          key=$(python -c 'from esphome.components.esp8266 import RECOMMENDED_ARDUINO_FRAMEWORK_VERSION as f; from esphome.arduino8266.framework import TOOLCHAIN_VERSION as t; print(f"{f}-{t}")')
+          [ -n "$key" ] || exit 1
+          echo "key=esp8266-native-$key" >> $GITHUB_OUTPUT
 
-      - name: Restore the native toolchain and ccache
+      - name: Restore the native toolchain
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: ~/.cache/esphome/arduino8266

esphome/components/esp8266/__init__.py

@@ -649,7 +649,12 @@ def _decode_pc(config, addr):
 
         idedata = toolchain.get_idedata(config)
         if not idedata.addr2line_path or not idedata.firmware_elf_path:
-            _LOGGER.debug("decode_pc no addr2line")
+            # Same visibility as the native branch: raw undecoded addresses
+            # with no stated reason are undiagnosable at default log level
+            _warn_decode_problem(
+                "no-addr2line",
+                "Cannot decode crash addresses: no addr2line or ELF in idedata",
+            )
             return
         addr2line, elf = idedata.addr2line_path, idedata.firmware_elf_path
     command = [addr2line, "-pfiaC", "-e", elf, addr]

tests/unit_tests/components/esp8266/test_toolchain_validation.py

@@ -139,6 +139,26 @@ def test_decode_pc_native_missing_tools_warns_once(
     esp8266._DECODE_WARNED_AT.clear()
 
 
+def test_decode_pc_platformio_missing_tools_warns_once(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """The PlatformIO branch reports a missing addr2line/ELF at the same
+    warning level as the native one; raw undecoded addresses with no
+    stated reason are undiagnosable at default log level."""
+    from types import SimpleNamespace
+
+    from esphome.components import esp8266
+
+    esp8266._DECODE_WARNED_AT.clear()
+    CORE.toolchain = Toolchain.PLATFORMIO
+    idedata = SimpleNamespace(addr2line_path=None, firmware_elf_path=None)
+    with patch("esphome.platformio.toolchain.get_idedata", return_value=idedata):
+        esp8266._decode_pc({}, "40201234")
+        esp8266._decode_pc({}, "40201238")
+    assert caplog.text.count("Cannot decode crash addresses") == 1
+    esp8266._DECODE_WARNED_AT.clear()
+
+
 def test_resolve_toolchain_rejects_unsupported() -> None:
     """ESP8266 rejects a CLI toolchain it cannot serve, like every platform."""
     from esphome.components.esp8266 import _resolve_toolchain