add cargo-all-features to container

Some crates have a myriad of features, and it is very easy to
accidentally mess up imports in a way that `cargo check --all-features`
works, but only compiling with only a subset of features breaks. For
this scenario, cargo check-all-features can help, as it will attempt to
compile all feature permutations.

We cannot currently add this to the default CI, as some crates in the
rust-vmm ecosystem have incompatible features [1], but this unlocks at
least testing all feature combinations for specific crates (for example,
to ensure that no-std support does not accidentally break [2]).

once the vm-memory / xen situation is fixed, this can also be added to
the default CI.

[1]: rust-vmm/vm-memory#317
[2]: rust-vmm/vm-allocator#107

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

build_container.sh

@@ -97,6 +97,8 @@ if [ "$ARCH" != "riscv64" ]; then
     popd
 fi
 
+cargo install cargo-all-features
+
 # Install some dependencies required by vhost-device crates but not available
 # in Ubuntu repos.
 # Some of these do not support riscv64, since vhost-device crates do not