Can't handle capitalised rename

[hottea773]

🐛 Bug description

Given the following main.rs:

#[derive(serde::Deserialize, Clone, Debug, serde::Serialize)]
pub struct Person {
    #[serde(rename(deserialize = "surname"))]
    pub surname: String,
    #[serde(skip_serializing, rename(deserialize = "FIRST_NAME"))]
    pub first_name: String,
}


fn main() -> anyhow::Result<()> {

    println!("FIRST_NAME: {}", std::env::var("FIRST_NAME").unwrap());
    println!("surname: {}", std::env::var("surname").unwrap());

    let person = envy::from_env::<Person>().map_err(|e| {
        anyhow::anyhow!(e).context("Could not read Person from environment")
    })?;

    println!("Person: {:?}", person);

    Ok(())
}

it fails to read the FIRST_NAME environment variable:

$ surname=smith FIRST_NAME=john cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/envy_bug`
FIRST_NAME: john
surname: smith
Error: Could not Person from environment

Caused by:
    missing value for field FIRST_NAME

🤔 Expected Behavior

It should have been able to read the FIRST_NAME environment variable.

👟 Steps to reproduce

Run the above code.

🌍 Your environment

I used the following Cargo.toml:

[package]
name = "envy_bug"
version = "0.1.0"
authors = ["hottomato4"]
edition = "2018"
publish = ["github"]

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]

serde = { version = "1", features = [ "derive" ] }
envy = "0.4"
anyhow = "1"

and the following Cargo.lock

# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
[[package]]
name = "anyhow"
version = "1.0.40"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "28b2cd92db5cbd74e8e5028f7e27dd7aa3090e89e4f2a197cc7c8dfb69c7063b"

[[package]]
name = "envy"
version = "0.4.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "3f47e0157f2cb54f5ae1bd371b30a2ae4311e1c028f575cd4e81de7353215965"
dependencies = [
 "serde",
]

[[package]]
name = "envy_bug"
version = "0.1.0"
dependencies = [
 "anyhow",
 "envy",
 "serde",
]

[[package]]
name = "proc-macro2"
version = "1.0.27"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f0d8caf72986c1a598726adc988bb5984792ef84f5ee5aa50209145ee8077038"
dependencies = [
 "unicode-xid",
]

[[package]]
name = "quote"
version = "1.0.9"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
dependencies = [
 "proc-macro2",
]

[[package]]
name = "serde"
version = "1.0.126"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ec7505abeacaec74ae4778d9d9328fe5a5d04253220a85c4ee022239fc996d03"
dependencies = [
 "serde_derive",
]

[[package]]
name = "serde_derive"
version = "1.0.126"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "963a7dbc9895aeac7ac90e74f34a5d5261828f79df35cbed41e10189d3804d43"
dependencies = [
 "proc-macro2",
 "quote",
 "syn",
]

[[package]]
name = "syn"
version = "1.0.72"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a1e8cdbefb79a9a5a65e0db8b47b723ee907b7c7f8496c76a1770b5c310bab82"
dependencies = [
 "proc-macro2",
 "quote",
 "unicode-xid",
]

[[package]]
name = "unicode-xid"
version = "0.2.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
[[package]]
name = "anyhow"
version = "1.0.40"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "28b2cd92db5cbd74e8e5028f7e27dd7aa3090e89e4f2a197cc7c8dfb69c7063b"

[[package]]
name = "envy"
version = "0.4.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "3f47e0157f2cb54f5ae1bd371b30a2ae4311e1c028f575cd4e81de7353215965"
dependencies = [
 "serde",
]

[[package]]
name = "envy_bug"
version = "0.1.0"
dependencies = [
 "anyhow",
 "envy",
 "serde",
]

[[package]]
name = "proc-macro2"
version = "1.0.27"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "f0d8caf72986c1a598726adc988bb5984792ef84f5ee5aa50209145ee8077038"
dependencies = [
 "unicode-xid",
]

[[package]]
name = "quote"
version = "1.0.9"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
dependencies = [
 "proc-macro2",
]

[[package]]
name = "serde"
version = "1.0.126"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ec7505abeacaec74ae4778d9d9328fe5a5d04253220a85c4ee022239fc996d03"
dependencies = [
 "serde_derive",
]

[[package]]
name = "serde_derive"
version = "1.0.126"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "963a7dbc9895aeac7ac90e74f34a5d5261828f79df35cbed41e10189d3804d43"
dependencies = [
 "proc-macro2",
 "quote",
 "syn",
]

[[package]]
name = "syn"
version = "1.0.72"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a1e8cdbefb79a9a5a65e0db8b47b723ee907b7c7f8496c76a1770b5c310bab82"
dependencies = [
 "proc-macro2",
 "quote",
 "unicode-xid",
]

[[package]]
name = "unicode-xid"
version = "0.2.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"

Also:

$ rustup show
Default host: x86_64-unknown-linux-gnu
rustup home:  /opt/rust

installed targets for active toolchain
--------------------------------------

x86_64-unknown-linux-gnu
x86_64-unknown-linux-musl

active toolchain
----------------

stable-x86_64-unknown-linux-gnu (default)
rustc 1.52.1 (9bc8c42bb 2021-05-09)
$ cargo --version
cargo 1.52.0 (69767412a 2021-04-21)

[alakhpc]

Is there any solution for this yet? seems like this is still there