[tlbuild] How to properly regenerate configure files?

[Mojca Miklavec]

On 14 July 2016 at 14:33, Norbert Preining wrote:
> Forgot ..
>
>> I tried to patch
>>     texk/gregorio/gregorio-src/configure.ac
>> but I guess I would have to modify
>>     texk/gregorio/configure.ac
>> instead?
>
> Yes, I think so.

I need some guidance then. The files differ a lot and it's not clear
to me which differences are desired and which ones are not.

Could someone who knows what he's doing perhaps synchronize the top
level configure.ac with the "upstream" version that's already in the
TL source tree one directory lower (gregorio-src/configure.ac)? It
will get slightly easier then to apply just a single line.

Thank you,
    Mojca