Merge branch 'patch5' into 'master'

fix(mk/ci.mk): set `COOKBOOK_HOST_SYSROOT` and `COOKBOOK_PREFER_STATIC`

See merge request redox-os/redox!1546

mk/ci.mk

@@ -27,6 +27,8 @@ ci-pkg: prefix FORCE
 	$(HOST_CARGO) build --manifest-path cookbook/pkgar/Cargo.toml --release
 	$(HOST_CARGO) build --manifest-path installer/Cargo.toml --release
 	export PATH="$(PREFIX_PATH):$$PATH" && \
+	export COOKBOOK_HOST_SYSROOT="$(ROOT)/$(PREFIX_INSTALL)" && \
+	export COOKBOOK_PREFER_STATIC="$(PREFER_STATIC)" && \
 	PACKAGES="$$($(INSTALLER) --list-packages -c config/$(ARCH)/ci.toml)" && \
 	cd cookbook && \
 	./fetch.sh "$${PACKAGES}" && \