Add robustness to the version calculations

CMakeLists.txt

@@ -11,7 +11,19 @@ execute_process(
     COMMAND scripts/version.sh
     WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
     OUTPUT_VARIABLE PACKAGE_VERSION
+    RESULT_VARIABLE GIT_ERROR_CODE
 )
+if (NOT GIT_ERROR_CODE EQUAL 0)
+    # - if we can run version.sh and it exits with an error that is signaling
+    #   a build failure.
+    # - if we are on windows with no MSYS or Cygwin, we cannot run version.sh
+    #   which is the fallback case handled below
+    # TODO: Distinguish between these two cases
+
+    # Fallback to just using the non dynamic short version string
+    file(STRINGS VERSION PACKAGE_VERSION)
+endif (NOT GIT_ERROR_CODE EQUAL 0)
+
 string(STRIP "${PACKAGE_VERSION}" PACKAGE_VERSION)
 MESSAGE(STATUS "Build for version: ${PACKAGE_VERSION}")
 

Makefile.in

@@ -148,7 +148,14 @@ COVERAGEDIR?=coverage
 .PHONY: steps build push all clean distclean install test cover gcov build-dep
 .PHONY: lint lint.python lint.ccode lint.shell lint.yaml
 
-all: $(APPS) $(DOCS) $(SUBDIRS)
+all: version $(APPS) $(DOCS) $(SUBDIRS)
+
+# This allows breaking the build if the version.sh script discovers
+# any inconsistancies
+.PHONY: version
+version:
+	@echo -n "Build for version: "
+	@scripts/version.sh
 
 tools: $(N2N_LIB)
 	$(MAKE) -C $@