cargo backup

backup and restore $CARGO_HOME cache to cargo_bak.zip cargo restore for custom docker ci

list of backup directories:

   $CARGO_HOME/registry/index/
   $CARGO_HOME/registry/cache/
   $CARGO_HOME/git/db/

usage:

• backup

cargo-bak bak
cargo-bak bak -s [filename]

• backup zip compression level default 0
• change compression level use -c

cargo-bak bak -c 6

• restore

  cargo-bak restore ./cargo_bak.zip