Unify version strings for legacy builds

.gitattributes

@@ -1,5 +1,6 @@
 # Substitions for git archive
 src/Makefile.in export-subst
+src/Makefile.legacy export-subst
 
 # Files/directories to be ignored for git archive
 .circle export-ignore

src/Makefile.legacy

@@ -30,9 +30,15 @@ SORT = sort
 STRIP = strip
 MAKE_ORIG = +$(MAKE) -f Makefile.legacy
 
-JTR_GIT_VERSION = \"$(shell git describe --tags --dirty=+ 2>/dev/null)\"
-ifeq ($(JTR_GIT_VERSION), \"\")
-JTR_GIT_VERSION = JUMBO_VERSION
+JTR_GIT_COMMIT = \"-$(shell git rev-parse --short HEAD 2>/dev/null)\"
+ifeq ($(JTR_GIT_COMMIT), \"-\")
+F = "" # for tarballs or zip files not created using git archive
+# this format string will be replaced by git archive:
+JTR_ARCHIVE_VERSION_STRING = $Format:-%h %ci$
+JTR_GIT_VERSION = JUMBO_VERSION "\"$(shell echo "$(JTR_ARCHIVE_VERSION_STRING)" | "$(SED)" 's/ormat:-%h %ci/-/g')\""
+else
+JTR_GIT_HEAD_TS = \" $(shell git show -s --format=%ci HEAD 2>/dev/null)\"
+JTR_GIT_VERSION = JUMBO_VERSION "$(JTR_GIT_COMMIT) $(JTR_GIT_HEAD_TS)"
 endif
 
 ## Uncomment the line below for MPI (can be used together with OMP as well)