transient build error after 'Writing MYMETA.yml and MYMETA.json'

I have not seen this before, which makes me think it is something new
in the makefiles.  But maybe it was a one-time fluke. When I ran
'make' again, it proceeded as normal.

My previous build was on pre-rebase 'next' at c1ece63.  I did not try
a 'make clean' in between, but I have since.  I tried to reproduce it
and I cannot.  I am building on Ubuntu 12.04.

I do not see any significant differences in the Makefile between my
last build point and this one.

Is this expected or easily explained?

$ make prefix=/home/hordp all doc man
...
    GEN git-add--interactive
Writing perl.mak for Git
Writing MYMETA.yml and MYMETA.json
make[2]: *** [perl.mak] Error 1
make[1]: *** [instlibdir] Error 2
make: *** [git-add--interactive] Error 2
$ make prefix=/home/hordp all doc man
    GEN perl/PM.stamp
    SUBDIR perl
/usr/bin/perl Makefile.PL PREFIX='/home/hordp' INSTALL_BASE=''
--localedir='/home/hordp/share/locale'
Writing perl.mak for Git
Writing MYMETA.yml and MYMETA.json
    GEN git-add--interactive
    GEN git-difftool
    GEN git-archimport


Phil