+export LD_LIBRARY_PATH:=$(subst ::,:,$(if $(LD_LIBRARY_PATH),$(LD_LIBRARY_PATH):)$(STAGING_DIR_HOST)/lib)
+export DYLD_LIBRARY_PATH:=$(subst ::,:,$(if $(DYLD_LIBRARY_PATH),$(DYLD_LIBRARY_PATH):)$(STAGING_DIR_HOST)/lib)
+export GIT_CONFIG_PARAMETERS='core.autocrlf=false'
+export MAKE_JOBSERVER=$(filter --jobserver%,$(MAKEFLAGS))
+
+# prevent perforce from messing with the patch utility
+unexport P4PORT P4USER P4CONFIG P4CLIENT
+
+# prevent user defaults for quilt from interfering
+unexport QUILT_PATCHES QUILT_PATCH_OPTS
+
+unexport C_INCLUDE_PATH CROSS_COMPILE ARCH
+
+# prevent distro default LPATH from interfering
+unexport LPATH
+
+# make sure that a predefined CFLAGS variable does not disturb packages
+export CFLAGS=
+
+ifneq ($(shell $(HOSTCC) 2>&1 | grep clang),)
+ export HOSTCC_REAL?=$(HOSTCC)
+ export HOSTCC_WRAPPER:=$(TOPDIR)/scripts/clang-gcc-wrapper
+else
+ export HOSTCC_WRAPPER:=$(HOSTCC)
+endif