From de4c139859e7523c7d9c4d736554e0a588c0dcfe Mon Sep 17 00:00:00 2001
From: wanjinhao1 <394959433@qq.com>
Date: Fri, 30 Oct 2026 09:14:54 +0800
Subject: [PATCH] Fix #16368: stop exporting ESLINT_FLAGS so ESLint does not
 parse it as feature flags

GNU make exports command-line variables as environment variables to
recipes. ESLint 9.39+ reads the ESLINT_FLAGS environment variable to
enable feature flags, so passing ESLINT_FLAGS='--quiet' on the make
command line (as the CI lint retry does) made ESLint fail with
"Unknown flag '--quiet'". Unexport the variable so it is only used to
build the ESLint command-line options.
---
 tools/make/lib/lint/javascript/eslint.mk | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/make/lib/lint/javascript/eslint.mk b/tools/make/lib/lint/javascript/eslint.mk
index 49624a7a4ee4..66bcabd08846 100644
--- a/tools/make/lib/lint/javascript/eslint.mk
+++ b/tools/make/lib/lint/javascript/eslint.mk
@@ -36,6 +36,12 @@ eslint_flags := \
 # Define user-supplied command-line options:
 ESLINT_FLAGS ?=
 
+# Ensure the `ESLINT_FLAGS` variable is not exported to the environment of invoked commands:
+#
+# -   ESLint 9.39+ reads the `ESLINT_FLAGS` environment variable to enable feature flags (e.g., `unstable_native_nodejs_ts_config`) and throws `Unknown flag` for anything unrecognized.
+# -   GNU `make` exports command-line variables as environment variables to recipes, so `make ESLINT_FLAGS=--quiet` would otherwise cause `--quiet` to be interpreted as a feature flag instead of a command-line option.
+unexport ESLINT_FLAGS
+
 ifeq ($(AUTOFIX),true)
 	eslint_flags += --fix
 endif