This streamlines the code base to follow best practices for
error handling in Rust: Each error struct implements
std::error::Error (most due via thiserror::Error derive macro)
and sets its source accordingly.
This allows future work that nicely prints the error chains,
for example.
So far, the convention is that each error prints its
sub error as part of its Display::fmt() impl.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
Rust 2021 edition has a few improvements over the 2018 edition. Migrate
the project to 2021 edition by following recommended migration steps.
Luckily, the code itself doesn't require fixing.
Bump MSRV to 1.56 as it is required by the 2021 edition. Also fix the
clap build dependency to make Cloud Hypervisor build again.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Remove the vmm dependency from vhost_user_block and vhost_user_net where
it was existing to use config::OptionParser. By moving the OptionParser
to its own crate at the top-level we can remove the very heavy
dependency that these vhost-user backends had.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
