rav1e: clean slackbuild?

There has been a big day for av1 encoding with rav1e putting out a release version and the latest FFmpeg adding a librav1e encoder. I am running both here on -current but a 'clean' slackbuild has escaped me as my experience packaging with cargo is pretty negligible.

Does anybody have a solution to cargo downloading a dozen or so 'crates' (fine on my system but not a technically nice, offline slackbuild) and then building a package for rav1e?

Originally Posted by andrew.46 Does anybody have a solution to cargo downloading a dozen or so 'crates' (fine on my system but not a technically nice, offline slackbuild) and then building a package for rav1e?

I did a quick grep through the SBo repo and there seems to be a few references you can use to deal with a cargo build system.

https://slackbuilds.org/slackbuilds/...cer.SlackBuild
https://slackbuilds.org/slackbuilds/...dor.SlackBuild
https://slackbuilds.org/slackbuilds/...tup.SlackBuild
https://slackbuilds.org/slackbuilds/...col.SlackBuild

Looks like one of the key things is adding the following to the script so it will look in a local directory for the crates rather than online:

# build offline
# configuration tells cargo to use the configured directory
# for dependencies instead of downloading from crates.io
mkdir .cargo
cat << EOF >> .cargo/config
[source.crates-io]
registry = 'https://github.com/rust-lang/crates.io-index'
replace-with = 'vendored-sources'

[source.vendored-sources]
directory = '$(pwd)/vendor'
EOF

OIC, does not look so bad. Mind you rav1e has a mind-altering list of crates to process. Another option for me would be to package these by using 'cargo fetch' first and then creating an archive...

Edit: Needs a double build to also produce headers for FFmpeg and friends. Cargo is not the easiest to massage into a distro-specific package