[opus] Unknown versions in git.

[bat guano]

----------------------------------------

> dnl The package_version file will be automatically synced to the git
> revision
> dnl by the update_version script when configured in the repository,

Not working for me.
:-(

This:-
$ git clone --depth 1 git://git.xiph.org/opus.git
$ cd opus
$ ./autogen.sh
$ ./configure

Then this:-
$ cat package_version | grep "PACKAGE_VERSION"
PACKAGE_VERSION="unknown"


Also...

This:-
$ git clone --depth 1 git://git.xiph.org/opus-tools.git
$ cd opus-tools
$ ./autogen.sh
$ ./configure

Then this:-
$ cat package_version | grep "PACKAGE_VERSION"
PACKAGE_VERSION="unknown"