Bizarre behavior on git commit

I'm running into a weird issue in a specific repo where "git show-ref" usage is being displayed after invocating "git commit".

E.g.
$ git commit -m "my commit message"
usage: git show-ref [-q|--quiet] [--verify] [--head]
[-d|--dereference] [-s|--hash[=<n>]] [--abbrev[=<n>]] [--tags]
[--heads] [--] [pattern*]
   or: git show-ref --exclude-existing[=pattern] < ref-list

    --tags                only show tags (can be combined with heads)
    --heads               only show heads (can be combined with tags)
    --verify              stricter reference checking, requires exact ref path
    --head                show the HEAD reference
    -d, --dereference     dereference tags into object IDs
    -s, --hash[=<n>]      only show SHA1 hash using <n> digits
    --abbrev[=<n>]        use <n> digits to display SHA-1s
    -q, --quiet           be quiet
    --exclude-existing[=<pattern>]
                          show refs from stdin that aren't in local repository

[master 28a735f] my commit message
 1 files changed, 2 insertions(+), 0 deletions(-)
$

This happens for every commit in this repository. I looked through the git source and failed to find any reference to git show-ref (or anything related to it) in buildin/commit.c. I gave up my search in hope that someone on the git list would have a better idea. I'm running version 1.7.0.3.311.g6a6955.

-Dan