Panic on curious [patch] combination

Problem

$ cargo build
thread 'main' panicked at 'not currently active!?', src/tools/cargo/src/cargo/core/resolver/mod.rs:825:36
stack backtrace:
   0: rust_begin_unwind
             at /rustc/fc2daaae610b5515438b551a2f3706196a997f35/library/std/src/panicking.rs:483
   1: core::panicking::panic_fmt
             at /rustc/fc2daaae610b5515438b551a2f3706196a997f35/library/core/src/panicking.rs:85
   2: core::option::expect_failed
             at /rustc/fc2daaae610b5515438b551a2f3706196a997f35/library/core/src/option.rs:1226
   3: cargo::core::resolver::activate_deps_loop
   4: cargo::core::resolver::resolve
   5: cargo::ops::resolve::resolve_with_previous
   6: cargo::ops::resolve::resolve_with_registry
   7: cargo::ops::resolve::resolve_ws_with_opts
   8: cargo::ops::cargo_compile::create_bcx
   9: cargo::ops::cargo_compile::compile_ws
  10: cargo::ops::cargo_compile::compile
  11: cargo::commands::build::exec
  12: cargo::cli::main
  13: cargo::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Steps

Try to build the following crate structure using Cargo.toml where ../wasmtime is a checkout of https://github.com/bytecodealliance/wasmtime.

# Cargo.toml
[package]
name = "headcrab"
version = "0.2.0"

[target.'cfg(target_os = "linux")'.dev-dependencies]
headcrab_inject = { path = "./headcrab_inject" }

[dev-dependencies]
rustc_codegen_cranelift = { path = "./cg_clif" }

[workspace]
exclude = ["./cg_clif"]

[patch.crates-io]
"cranelift-codegen" = { git = 'https://github.com/bytecodealliance/wasmtime/', branch = "main" }

[patch."https://github.com/bytecodealliance/wasmtime/"]
cranelift-codegen = { path = "../wasmtime/cranelift/codegen" }

# headcrab_inject/Cargo.toml
[package]
name = "headcrab_inject"
version = "0.2.0"

[dependencies]
headcrab = { version = "0.2.0", path = "../" }
cranelift-codegen = "0.67.0"

# cg_clif/Cargo.toml
[package]
name = "rustc_codegen_cranelift"
version = "0.1.0"

[dependencies]
# These have to be in sync with each other
cranelift-codegen = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main", features = ["unwind"] }

Notes

Output of cargo version: cargo 1.48.0-nightly (05c611ae3 2020-09-23)

Start with src/tools/cargo/src/cargo/core/resolver/mod.rs at line 825 and reproduce the panic using the three Cargo.toml files and cargo build described in the issue. Trace the resolver path from activate_deps_loop and verify that the reported crate combination completes without panicking; the issue provides no named regression test.