Check all requirements before exiting on error

Signed-off-by: Timothy Gu <timothygu99@gmail.com>

Makefile

@@ -183,25 +183,15 @@ all: all-filtered
 .PHONY: check-requirements
 define CHECK_REQUIREMENT
     @if ! $(1) --help &>/dev/null; then \
-        echo; \
         echo 'Missing requirement: $(1)'; \
-        echo; \
-        echo 'Please have a look at "index.html" to ensure'; \
-        echo 'that your system meets all requirements.'; \
-        echo; \
-        exit 1; \
+        touch check-requirements-failed; \
     fi
 
 endef
 define CHECK_REQUIREMENT_VERSION
     @if ! $(1) --version | head -1 | grep ' \($(2)\)$$' >/dev/null; then \
-        echo; \
         echo 'Wrong version of requirement: $(1)'; \
-        echo; \
-        echo 'Please have a look at "index.html" to ensure'; \
-        echo 'that your system meets all requirements.'; \
-        echo; \
-        exit 1; \
+        touch check-requirements-failed; \
     fi
 
 endef
@@ -213,6 +203,14 @@ $(PREFIX)/installed/check-requirements: $(MAKEFILE)
 	$(foreach REQUIREMENT,$(REQUIREMENTS),$(call CHECK_REQUIREMENT,$(REQUIREMENT)))
 	$(call CHECK_REQUIREMENT_VERSION,autoconf,2\.6[4-9]\|2\.[7-9][0-9])
 	$(call CHECK_REQUIREMENT_VERSION,automake,1\.11\.[3-9]\|1\.[1-9][2-9]\(\.[0-9]\+\)\?)
+	@if [ -e check-requirements-failed ]; then \
+	    echo; \
+        echo 'Please have a look at "index.html" to ensure'; \
+        echo 'that your system meets all requirements.'; \
+        echo; \
+	    rm check-requirements-failed; \
+	    exit 1; \
+	fi
 	@touch '$@'
 
 include $(patsubst %,$(TOP_DIR)/src/%.mk,$(PKGS))