Reset GREP_OPTIONS.
The build system needs unmodified output of grep.
Bug: 21260618
Change-Id: Ifab74e23dfbe23eb12aa053d95d44a5e4a0c97d5
diff --git a/core/config.mk b/core/config.mk
index c20a2a2..e44558e 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -31,6 +31,11 @@
# only has an effect on python 2.6 and above.
export PYTHONDONTWRITEBYTECODE := 1
+ifneq ($(GREP_OPTIONS),)
+$(warning The build system needs unmodified output of grep.)
+$(error Please unset your $GREP_OPTIONS.)
+endif
+
# Standard source directories.
SRC_DOCS:= $(TOPDIR)docs
# TODO: Enforce some kind of layering; only add include paths