Error running makeinfo

[Karl Berry]

Hi Jim,

    $ makeinfo MiscXS.c: loadable library and perl binaries are mismatched
    (got handshake key 0xdb00080, needed 0xde00080)

Indeed, when Perl gets updated (at least in a big enough way), Texinfo
also has to be updated. This is a consequence of Gavin using compiled C
code to make makeinfo faster. It's a hassle. I don't know why it does
not happen for other Perl packages that use compiled code (there are
many, after all, while makeinfo is the only one I ever have this problem
with).  Could be worth a report to bug-texinfo.

In any case, assuming you are using programs from distro packaging, this
seems like something that needs to be reported to Ubuntu.

Meanwhile, given the updated Perl, I think the "simplest" way forward
for now would be to download the original Texinfo distribution from
  http://ftp.gnu.org/gnu/texinfo/texinfo-6.7.tar.xz 
and run configure --prefix=/your/preferred/location && make && make install
That should pick up your new version of system Perl and be functional.
(At least, rebuilding Texinfo is all I do when I put in a new Perl.)

I don't think anything about your TeX Live installation matters here,
because we don't distribute either makeinfo or (apart from Windows) perl.
Let me know (off-list :) if problems persist. --best, karl.