cargo metadata output shouldn't filter by target in .cargo/config

[ComputerDruid]

Problem

When a conditional dependency exists in Cargo.toml:

[target.'cfg(not(target_os = "fuchsia"))'.dependencies]
smol = "0.1.11"

and a .cargo/config exists which sets a default target:

[build]
target = "x86_64-fuchsia"

The output of cargo metadata --format-version 1 is missing the dependencies pulled in by the conditional dep, but they shouldn't be.

Steps

$ cargo init cargo_metadata_example
$ cd cargo_metadata_example
$ cat <<EOF >> Cargo.toml
[target.'cfg(not(target_os = "fuchsia"))'.dependencies]
smol = "0.1.11"
EOF
$ mkdir .cargo
$ echo -e '[build]\ntarget = "x86_64-fuchsia"' > .cargo/config

$ cargo +beta metadata --format-version 1 | jq '.packages[] | .id' # Broken:
"cargo_metadata_example 0.1.0 (path+file:///usr/local/google/home/computerdruid/cargo_metadata_example)"

$ cargo +stable metadata --format-version 1 | jq '.packages[] | .id' # Works:
"pin-project 0.4.22 (registry+https://github.com/rust-lang/crates.io-index)"
"quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)"
"concurrent-queue 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)"
"winapi 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)"
"cargo_metadata_example 0.1.0 (path+file:///usr/local/google/home/computerdruid/cargo_metadata_example)"
"slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)"
"winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)"
"memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)"
"futures-sink 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)"
"parking 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)"
"blocking 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)"
"cache-padded 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)"
"cc 1.0.57 (registry+https://github.com/rust-lang/crates.io-index)"
"futures-io 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)"
"once_cell 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)"
"async-task 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)"
"smol 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)"
"pin-utils 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)"
"proc-macro2 1.0.18 (registry+https://github.com/rust-lang/crates.io-index)"
"futures-task 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)"
"futures-util 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)"
"futures-channel 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)"
"unicode-xid 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)"
"libc 0.2.71 (registry+https://github.com/rust-lang/crates.io-index)"
"scoped-tls 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)"
"futures-core 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)"
"socket2 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)"
"cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)"
"winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)"
"pin-project-internal 0.4.22 (registry+https://github.com/rust-lang/crates.io-index)"
"waker-fn 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)"
"redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)"
"syn 1.0.33 (registry+https://github.com/rust-lang/crates.io-index)"
"fastrand 1.3.3 (registry+https://github.com/rust-lang/crates.io-index)"
"wepoll-sys-stjepang 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)"

Notes

Output of cargo version:

$ cargo +beta --version
cargo 1.45.0-beta (744bd1fbb 2020-06-15)
$ cargo +stable --version
cargo 1.44.1 (88ba85757 2020-06-11)

• I also tested on nightly, it has the same bug.
• I used jq in the reproduction to make the output smaller and show what's missing, but jq isn't an important part of the repro, you can see the problem just by looking at the json output.

[tmandry]

This was a stable-to-beta regression and is now a stable-to-stable regression, I think it needs to be marked as such.