Bump buildroot to version 2018.02.8

bsp/buildroot/Makefile

@@ -60,6 +60,11 @@ override O := $(patsubst %/,%,$(patsubst %.,%,$(O)))
 # avoid empty CANONICAL_O in case on non-existing entry.
 CANONICAL_O := $(shell mkdir -p $(O) >/dev/null 2>&1)$(realpath $(O))
 
+# gcc fails to build when the srcdir contains a '@'
+ifneq ($(findstring @,$(CANONICAL_O)),)
+$(error The build directory can not contain a '@')
+endif
+
 CANONICAL_CURDIR = $(realpath $(CURDIR))
 
 REQ_UMASK = 0022
@@ -87,9 +92,9 @@ all:
 .PHONY: all
 
 # Set and export the version string
-export BR2_VERSION := 2018.02.6
+export BR2_VERSION := 2018.02.8
 # Actual time the release is cut (for reproducible builds)
-BR2_VERSION_EPOCH = 1538896000
+BR2_VERSION_EPOCH = 1543272000
 
 # Save running make version since it's clobbered by the make package
 RUNNING_MAKE_VERSION := $(MAKE_VERSION)
@@ -355,8 +360,14 @@ export HOSTARCH := $(shell LC_ALL=C $(HOSTCC_NOCCACHE) -v 2>&1 | \
 	    -e 's/macppc/powerpc/' \
 	    -e 's/sh.*/sh/' )
 
-HOSTCC_VERSION := $(shell $(HOSTCC_NOCCACHE) --version | \
-	sed -n -r 's/^.* ([0-9]*)\.([0-9]*)\.([0-9]*)[ ]*.*/\1 \2/p')
+# When adding a new host gcc version in Config.in,
+# update the HOSTCC_MAX_VERSION variable:
+HOSTCC_MAX_VERSION := 8
+
+HOSTCC_VERSION := $(shell V=$$($(HOSTCC_NOCCACHE) --version | \
+	sed -n -r 's/^.* ([0-9]*)\.([0-9]*)\.([0-9]*)[ ]*.*/\1 \2/p'); \
+	[ "$${V%% *}" -le $(HOSTCC_MAX_VERSION) ] || V=$(HOSTCC_MAX_VERSION); \
+	printf "%s" "$${V}")
 
 # For gcc >= 5.x, we only need the major version.
 ifneq ($(firstword $(HOSTCC_VERSION)),4)