Panic when trying to deserialize a JSON map field while the actual config contains a non-map type

I have the following enum in my code:

#[derive(Clone, Debug, Deserialize, Serialize)]
#[serde(rename_all = "lowercase")]
pub enum my_enum {
    Foo { field: String },
    Bar { field: String }
}

And am trying to parse it in my configuration file, which had erroneous input:

...
 "my_field": "foo",
...

(instead of {"foo": {...}})

This caused the following panic:

thread 'main' panicked at 'internal error: entered unreachable code', /home/administrator/.cargo/registry/src/github.com-1ecc6299db9ec823/config-0.11.0/src/de.rs:335:18
stack backtrace:
   0: rust_begin_unwind
             at /rustc/3c5e68de8aeb3970cd32ff45fd5d00ccc14da060/library/std/src/panicking.rs:515:5
   1: core::panicking::panic_fmt
             at /rustc/3c5e68de8aeb3970cd32ff45fd5d00ccc14da060/library/core/src/panicking.rs:92:14
   2: core::panicking::panic
             at /rustc/3c5e68de8aeb3970cd32ff45fd5d00ccc14da060/library/core/src/panicking.rs:50:5
   3: <config::de::EnumAccess as serde::de::VariantAccess>::struct_variant
   4: <config::de::MapAccess as serde::de::MapAccess>::next_value_seed
   5: venom::settings::opts::_::<impl serde::de::Deserialize for venom::settings::opts::InferenceSettings>::deserialize
   6: <config::de::MapAccess as serde::de::MapAccess>::next_value_seed
   7: venom::settings::opts::_::<impl serde::de::Deserialize for venom::settings::opts::GeneralSettings>::deserialize
   8: project::config::EnvironmentConfigBuilder::build
   9: venom::settings::opts::Settings::from_commandline_arguments
  10: venom::main

Probably a simple fix, just return an error in <config::de::EnumAccess as serde::de::VariantAccess>::struct_variant and its related functions instead of panicking.

Start in de.rs around the EnumAccess and VariantAccess implementation, especially struct_variant near line 335, and inspect the related functions for the same unreachable path. Reproduce deserialization with a string where a map-shaped enum value is expected; done means invalid input returns a deserialization error instead of panicking.