Describe the bug
The latest changes and the release of 0.8.7 have introduced some issues.

• 0.8.7 does not compile with the nightly feature anymore. See compile errors attached.
• I think this could cause the issue
• locking the version to eg. "=0.8.6" fails because of incompatibilities with leptos-config because of this commit
• compiling on stable seems to work for 0.8.7.
• compiling on nightly without the "nightly" feature works as well

Leptos Dependencies

Please copy and paste the Leptos dependencies and features from your Cargo.toml.

For example:

[package]
name = "leptos-test-crate"
version = "0.1.0"
edition = "2024"

[dependencies]
leptos = { version = "0.8.7", features = ["nightly"] }

To Reproduce
Steps to reproduce the behavior:

1. cargo new cargo-test-crate
2. cd cargo-test-crate
3. cargo add leptos -F nightly
4. cargo +nightly check

Additional context
Add any other context about the problem here.

# rustup show

Default host: x86_64-pc-windows-msvc
rustup home:  C:\Users\nunre\.rustup

installed toolchains
--------------------
stable-x86_64-pc-windows-msvc
nightly-x86_64-pc-windows-msvc (active, default)
1.77-x86_64-pc-windows-msvc
1.81-x86_64-pc-windows-msvc

active toolchain
----------------
name: nightly-x86_64-pc-windows-msvc
active because: it's the default toolchain
installed targets:
  wasm32-unknown-unknown
  wasm32-wasip1
  x86_64-pc-windows-msvc

# rustc -V
rustc 1.91.0-nightly (54c581243 2025-08-25)

compiler_error.txt