`(package-build-all)` succeeds but prints about the building package failed

[ramboman]

(package-build-all) builds correctly the archive, but it prints:

...
Successfully built 0 of 1 packagesBuilding 1 packages failed:

at the end of the output.

Here is the structure of my personal melpa directory:

<personal-melpa-dir>
 |- archive
 |   \- (empty)
 |- recipes
 |   \- smex
 \- working
     \- (empty)

recipes/smex:

(smex :repo "nonsequitur/smex" :fetcher github)

test.el

#!emacs --script

(add-to-list 'load-path "<package-build-git-repo-dir>")

(require 'package-build)

(setq local-melpa-dir "<personal-melpa-dir>")
(setq package-build-archive-dir (expand-file-name "archive" local-melpa-dir))
(setq package-build-recipes-dir (expand-file-name "recipes" local-melpa-dir))
(setq package-build-working-dir (expand-file-name "working" local-melpa-dir))

(package-build-all)

Here are other things I have noticed:

• The output Successfully built 0 of 1 packages is right beside Building 1 packages failed:. Should there be an \n at the end of the format template here?
• Is it supposed to be failed instead of invalid here?

package-build commit: 0a22c3f

[tarsius]

Sorry this took so long.