Please provide an option to not depend on downloading model data

We build opus from git source and we'd like to not switch to tarballs or download the model tarball. Given the recent xz situation downloading tarballs with no trace on git is complicated and seems like a security issue.

Having an option to stop depending on that seems like it'd be great.

With the current meson configuration:

-Dfloat-api=true 
-Dasm=disabled 
-Dhardening=true 
-Dcustom-modes=true 
-Denable-deep-plc=true 
-Denable-dred=true 
-Denable-osce=true 
-Ddocs=enabled 
-Dextra-programs=disabled 
-Dtests=disabled 
-Dintrinsics=enabled 
-Drtcd=enabled

meson seems to fail on meson.build:636:24: ERROR: File dnn/fargan_data.h does not exist. and is not even aware of the download model script living in autogen.

Whereas the download model script is passing an unknown commit https://github.com/xiph/opus/blob/ab4e83598e7fc8b2ce82dc633a0fc0c452b629aa/autogen.sh#L12C24-L12C31

What is the source of that commit? Can this model data be found on git somewhere? Can this be implemented as a git submodule?

Looking through the git history seems at some point there was a submodule, which was reverted in favour of downloading the model tarball.

Thanks!

Start with meson.build around line 636 and autogen.sh around line 12, then inspect the git history for the reverted model-data submodule. Reproduce the failure with the listed Meson options and trace how fargan_data.h is expected to appear. Done means a source build can use a traceable model-data source without downloading an untracked tarball.