From afdf97ca768933b8deb5cc30e3b2fa61e55da9b5 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Mon, 17 Sep 2018 11:10:54 -0700 Subject: [PATCH] Makefile: fix issue with printvars executing giant shell command MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The underlying problem is that $(foreach V,1 2 3,) does not evaluate to an empty string. It evaluates to "  ", three empty strings separated by whitespace. A construct of this format, with a giant list in the foreach, is part of the printvars command. This means that "@:$(foreach ....)", which is intended to expand to a null command, in fact expands to "@: " with a great deal of whitespace. Make chooses to execute this command with: execve("/bin/sh", ["/bin/sh", "-c", ": "] But with far more whitespace. So much that it can exceed shell command line length limits. This solution is to move the foreach to another step in the recipe. The "@:" is retained as the first line so the recipe is not Empty, which would cause a change in make behavior when make builds the target. The 2nd line, all whitespace, will be skipped by make. Signed-off-by: Trent Piepho Tested-by: "Yann E. MORIN" Acked-by: "Yann E. MORIN" Signed-off-by: Thomas Petazzoni (cherry picked from commit b8d0aadc6d52733cfc914ba3cd6f506238bd19f7) Signed-off-by: Peter Korsgaard --- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 5fb26c9733..dc26099fd4 100644 --- a/Makefile +++ b/Makefile @@ -976,7 +976,8 @@ $(BUILD_DIR)/.br2-external.in: $(BUILD_DIR) # displayed. .PHONY: printvars printvars: - @:$(foreach V, \ + @: + $(foreach V, \ $(sort $(if $(VARS),$(filter $(VARS),$(.VARIABLES)),$(.VARIABLES))), \ $(if $(filter-out environment% default automatic, \ $(origin $V)), \