diff --git a/docs/manual/customize-toolchain.txt b/docs/manual/customize-toolchain.txt
index 811a6dc7f9..82ecc28431 100644
--- a/docs/manual/customize-toolchain.txt
+++ b/docs/manual/customize-toolchain.txt
@@ -17,6 +17,17 @@ generate it.
 It also requires to set the Buildroot settings according to the toolchain ones
 (see xref:external-toolchain-backend[]).
 
+When using an external toolchain, Buildroot generates a wrapper program, that
+passes the appropriate options (according to the configuration) to the
+external toolchain programs. In case you need to debug this wrapper, you can
+set the environment variable BR_DEBUG_WRAPPER to either one of:
+
+* +0+, empty or not set: no debug
+
+* +1+: trace all arguments on a single line
+
+* +2+: trace one argument per line
+
 Using the internal Buildroot toolchain backend
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/toolchain/toolchain-external/ext-toolchain-wrapper.c b/toolchain/toolchain-external/ext-toolchain-wrapper.c
index 565e36bfd1..dfdfcffbf5 100644
--- a/toolchain/toolchain-external/ext-toolchain-wrapper.c
+++ b/toolchain/toolchain-external/ext-toolchain-wrapper.c
@@ -74,7 +74,8 @@ int main(int argc, char **argv)
 	char *relbasedir, *absbasedir;
 	char *progpath = argv[0];
 	char *basename;
-	int ret, i, count = 0;
+	char *env_debug;
+	int ret, i, count = 0, debug;
 
 	/* Calculate the relative paths */
 	basename = strrchr(progpath, '/');
@@ -157,13 +158,21 @@ int main(int argc, char **argv)
 	/* finish with NULL termination */
 	*cur = NULL;
 
-	if (getenv("BR_DEBUG_WRAPPER")) {
-		fprintf(stderr, "Executing");
-
-		for (i = 0; args[i]; i++)
-			fprintf(stderr, " %s", args[i]);
-
-		fprintf(stderr, "\n");
+	/* Debug the wrapper to see actual arguments passed to
+	 * the compiler:
+	 * unset, empty, or 0: do not trace
+	 * set to 1          : trace all arguments on a single line
+	 * set to 2          : trace one argument per line
+	 */
+	if ((env_debug = getenv("BR_DEBUG_WRAPPER"))) {
+		debug = atoi(env_debug);
+		if (debug > 0) {
+			fprintf(stderr, "Toolchain wrapper executing:");
+			for (i = 0; args[i]; i++)
+				fprintf(stderr, "%s'%s'",
+					(debug == 2)?"\n    ":" ", args[i]);
+			fprintf(stderr, "\n");
+		}
 	}
 
 	if (execv(path, args))