Index: tmp_buildroot-2016.05/package/bzip2/0100-avm-add-build-flags.patch
===================================================================
--- /dev/null
+++ tmp_buildroot-2016.05/package/bzip2/0100-avm-add-build-flags.patch
@@ -0,0 +1,38 @@
+--- a/Makefile	2017-11-24 16:21:17.003925954 +0100
++++ b/Makefile	2017-11-24 16:23:28.944774814 +0100
+@@ -18,9 +18,9 @@
+ CC=gcc
+ AR=ar
+ RANLIB=ranlib
+-LDFLAGS=
++override LDFLAGS += $(DEFAULT_LDFLAGS_APPL)
+ 
+-override CFLAGS += -Wall
++override CFLAGS += -Wall $(DEFAULT_CFLAGS_SRC)
+ 
+ # Where you want it installed when you do 'make install'
+ PREFIX=/usr/local
+
+--- ./Makefile-libbz2_so.orig	2017-12-01 12:45:39.385233416 +0100
++++ ./Makefile-libbz2_so	2017-12-01 12:48:05.949020606 +0100
+@@ -23,7 +23,7 @@
+ 
+ SHELL=/bin/sh
+ CC=gcc
+-override CFLAGS += -fpic -fPIC -Wall
++override CFLAGS += -fpic -fPIC -Wall $(DEFAULT_CFLAGS_LIB)
+ 
+ OBJS= blocksort.sho  \
+       huffman.sho    \
+@@ -34,8 +34,8 @@
+       bzlib.sho
+ 
+ all: $(OBJS)
+-	$(CC) -shared -Wl,-soname -Wl,libbz2.so.1.0 -o libbz2.so.1.0.6 $(OBJS)
+-	$(CC) $(CFLAGS) -o bzip2-shared bzip2.c libbz2.so.1.0.6
++	$(CC) $(DEFAULT_LDFLAGS_LIB) -shared -Wl,-soname -Wl,libbz2.so.1.0 -o libbz2.so.1.0.6 $(OBJS)
++	$(CC) $(DEFAULT_CFLAGS_SRC) $(DEFAULT_LDFLAGS_APPL) -o bzip2-shared bzip2.c libbz2.so.1.0.6
+ 
+ install:
+ 	install -m 0755 -D libbz2.so.1.0.6 $(PREFIX)/lib/libbz2.so.1.0.6
+
Index: tmp_buildroot-2016.05/package/bzip2/bzip2.mk
===================================================================
--- tmp_buildroot-2016.05.orig/package/bzip2/bzip2.mk
+++ tmp_buildroot-2016.05/package/bzip2/bzip2.mk
@@ -13,13 +13,13 @@ BZIP2_LICENSE_FILES = LICENSE
 ifeq ($(BR2_STATIC_LIBS),)
 define BZIP2_BUILD_SHARED_CMDS
 	$(TARGET_MAKE_ENV)
-		$(MAKE) -C $(@D) -f Makefile-libbz2_so $(TARGET_CONFIGURE_OPTS)
+		$(MAKE) -C $(@D) -f Makefile-libbz2_so $(TARGET_CONFIGURE_OPTS) CFLAGS="$(CFLAGS) $(DEFAULT_CFLAGS_LIB)" LDFLAGS="$(LDFLAGS) $(DEFAULT_LDFLAGS_LIB)"
 endef
 endif
 
 define BZIP2_BUILD_CMDS
 	$(TARGET_MAKE_ENV)
-		$(MAKE) -C $(@D) libbz2.a bzip2 bzip2recover $(TARGET_CONFIGURE_OPTS)
+		$(MAKE) -C $(@D) libbz2.a bzip2 bzip2recover $(TARGET_CONFIGURE_OPTS) CFLAGS="$(CFLAGS) $(DEFAULT_CFLAGS_SRC)" LDFLAGS="$(LDFLAGS) $(DEFAULT_LDFLAGS_APPL)"
 	$(BZIP2_BUILD_SHARED_CMDS)
 endef