Include Git Hash in PDF

["'Jan Ulrich Hasecke' via pandoc-discuss" <pandoc-discuss-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org>]

Hi all,

I am lost.

How can I insert the commit hash from git in the output file?

I tried to evaluate "git rev-parse HEAD" in a build script and hand over 
the result to the build process by setting a custom variable to the hash 
string via --variable hash=${git rev-parse HEAD}. In my template I have 
$hash$

I stored the hash in a file and tried to include it with -B, though this 
would not be a good solution if it worked at all.

I guess this is quite a common requirement but I failed to find the 
solution with Google & Co.

Any hints
juh