Fix issue with empty buildOrder

alibuild_helpers/build.py

@@ -540,9 +540,17 @@ def doBuild(args, parser):
     del develCandidates, develCandidatesUpper, develPkgsUpper
 
   if buildOrder:
-    banner("Packages will be built in the following order:\n - %s",
-           "\n - ".join(x+" (development package)" if x in develPkgs else "%s@%s" % (x, specs[x]["tag"])
-                        for x in buildOrder if x != "defaults-release"))
+    if args.onlyDeps: 
+      builtPackages = buildOrder[:-1]
+    else:
+      builtPackages = buildOrder
+    if len(builtPackages) > 1:
+      banner("Packages will be built in the following order:\n - %s",
+             "\n - ".join(x+" (development package)" if x in develPkgs else "%s@%s" % (x, specs[x]["tag"])
+                          for x in builtPackages if x != "defaults-release"))
+    else:
+      banner("No dependencies of package %s to build.", buildOrder[-1])
+
 
   if develPkgs:
     banner("You have packages in development mode (%s).\n"
@@ -1118,14 +1126,19 @@ def doBuild(args, parser):
     if not spec["revision"].startswith("local"):
       syncHelper.upload_symlinks_and_tarball(spec)
 
-  banner("Build of %s successfully completed on `%s'.\n"
-         "Your software installation is at:"
-         "\n\n  %s\n\n"
-         "You can use this package by loading the environment:"
-         "\n\n  alienv enter %s/latest-%s",
-         mainPackage, socket.gethostname(),
-         abspath(join(args.workDir, args.architecture)),
-         mainPackage, mainBuildFamily)
+  if not args.onlyDeps:
+      banner("Build of %s successfully completed on `%s'.\n"
+             "Your software installation is at:"
+             "\n\n  %s\n\n"
+             "You can use this package by loading the environment:"
+             "\n\n  alienv enter %s/latest-%s",
+             mainPackage, socket.gethostname(),
+             abspath(join(args.workDir, args.architecture)),
+             mainPackage, mainBuildFamily)
+  else:
+      banner("Successfully built dependencies for package %s on `%s'.\n",
+             mainPackage, socket.gethostname()
+            )
   for spec in specs.values():
     if spec["is_devel_pkg"]:
       banner("Build directory for devel package %s:\n%s/BUILD/%s-latest%s/%s",