From 24eb6354f937a19c4e8729065e9e19f8ed0b0a98 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Thu, 20 Aug 2026 23:47:47 -0500
Subject: [PATCH] Run validators when a CLI toolchain is given on the cache
 fast path, cover every LibreTiny family

---
 esphome/__main__.py                        |  6 +++++-
 tests/unit_tests/test_config_validation.py |  2 ++
 tests/unit_tests/test_main.py              | 17 +++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/esphome/__main__.py b/esphome/__main__.py
index 74f125ebf7..e3083a461a 100644
--- a/esphome/__main__.py
+++ b/esphome/__main__.py
@@ -2735,7 +2735,11 @@ def run_esphome(argv):
     # against the previous substitution set.
     config: ConfigType | None = None
     cache_eligible = (
-        args.command in ("upload", "logs") and not command_line_substitutions
+        args.command in ("upload", "logs")
+        and not command_line_substitutions
+        # An explicit CLI toolchain must run the per-platform validators;
+        # the cache was validated under whatever the last compile used
+        and args.toolchain is None
     )
     if cache_eligible:
         from esphome.compiled_config import load_compiled_config
diff --git a/tests/unit_tests/test_config_validation.py b/tests/unit_tests/test_config_validation.py
index 78fc39430e..6f98de2642 100644
--- a/tests/unit_tests/test_config_validation.py
+++ b/tests/unit_tests/test_config_validation.py
@@ -3200,6 +3200,8 @@ def test_check_supported_toolchain_unresolved_is_an_ordering_bug() -> None:
         ("host", {}),
         ("rp2", {"board": "rpipicow"}),
         ("bk72xx", {"board": "generic-bk7231n-qfn32-tuya"}),
+        ("rtl87xx", {"board": "generic-rtl8710bn-2mb-788k"}),
+        ("ln882x", {"board": "generic-ln882h"}),
         # The legacy stub platform must reject too, not just the chip families
         ("libretiny", {}),
     ],
diff --git a/tests/unit_tests/test_main.py b/tests/unit_tests/test_main.py
index b0cb5f6a0a..461370dff8 100644
--- a/tests/unit_tests/test_main.py
+++ b/tests/unit_tests/test_main.py
@@ -7230,3 +7230,20 @@ def test_compile_program_espidf_idedata_none_warns(
     ):
         assert compile_program(MagicMock(), {}) == 0
     assert "No idedata was generated" in caplog.text
+
+
+def test_cli_toolchain_skips_the_validated_config_cache(tmp_path: Path) -> None:
+    """An explicit --toolchain must run the per-platform validators, so the
+    upload/logs fast path becomes a cache miss."""
+    from esphome.__main__ import run_esphome
+
+    conf = tmp_path / "device.yaml"
+    conf.write_text("esphome:\n  name: t\n")
+    argv = ["esphome", "--toolchain", "arduino", "logs", str(conf)]
+    with (
+        patch("esphome.compiled_config.load_compiled_config") as mock_cache,
+        patch("esphome.config.read_config", return_value=None) as mock_read,
+    ):
+        assert run_esphome(argv) == 2
+    mock_cache.assert_not_called()
+    mock_read.assert_called_once()