ensure fresh build of zcash_client_backend dep in CI

[borngraced]

zcash_client_backend dependency is sometimes fetched from a cached location during CI operations, which leads to error like file not found for module compact_formats in z_coin and causes CI to fail.

I have two possible solutions, which involves running one of these command just before cargo /test/build/test commands

rm -rf ~/.cargo/git/checkouts/librustzcash*

or

cargo update -p zcash_client_backend

[shamardy]

With this we wouldn't need to remove caching in CI. I was about to remove CI caching, great find!

[dimxy]

I saw this issue couple times.
I noticed compact_formats.rs is a generated src by the build.rs. Perhaps build.rs fails to run sometimes, so there is no compact_formats.rs in the .cargo/git/checkouts/librustzcash installation.

BTW the original zcash/librustzcash now has this compact_formats.rs added in the repo.

[borngraced]

I saw this issue couple times. I noticed compact_formats.rs is a generated src by the build.rs. Perhaps build.rs fails to run sometimes, so there is no compact_formats.rs in the .cargo/git/checkouts/librustzcash installation.

BTW the original zcash/librustzcash now has this compact_formats.rs added in the repo.

deleting https://github.com/KomodoPlatform/librustzcash/blob/master/zcash_client_backend/.gitignore could another solution too! cc @dimxy