Hi all,

After merging the net-next tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

scripts/link-vmlinux.sh: 74: Bad substitution

Caused by commit

  341dfcf8d78e ("btf: expose BTF info through sysfs")

interacting with commit

  1267f9d3047d ("kbuild: add $(BASH) to run scripts with bash-extension")

from the kbuild tree.

The change in the net-next tree turned link-vmlinux.sh into a bash script
(I think).

I have applied the following patch for today:

From: Stephen Rothwell <sfr@canb.auug.org.au>
Date: Wed, 4 Sep 2019 15:43:41 +1000
Subject: [PATCH] link-vmlinux.sh is now a bash script

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 Makefile                | 4 ++--
 scripts/link-vmlinux.sh | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index ac97fb282d99..523d12c5cebe 100644
--- a/Makefile
+++ b/Makefile
@@ -1087,7 +1087,7 @@ ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
 
 # Final link of vmlinux with optional arch pass after final link
 cmd_link-vmlinux =                                                 \
-	$(CONFIG_SHELL) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ;    \
+	$(BASH) $< $(LD) $(KBUILD_LDFLAGS) $(LDFLAGS_vmlinux) ;    \
 	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
 
 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
@@ -1403,7 +1403,7 @@ clean: rm-files := $(CLEAN_FILES)
 PHONY += archclean vmlinuxclean
 
 vmlinuxclean:
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
+	$(Q)$(BASH) $(srctree)/scripts/link-vmlinux.sh clean
 	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
 
 clean: archclean vmlinuxclean
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index f7edb75f9806..ea1f8673869d 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 #
 # link vmlinux
-- 
2.23.0.rc1

-- 
Cheers,
Stephen Rothwell