"hyper" is being rebuilt on each `cargo miri run`

[RalfJung]

To reproduce, do cargo init to create a new project, and replace the Cargo.toml file by

[package]
name = "playground"
version = "0.0.1"
authors = ["The Rust Playground"]

[dependencies.hyper]
package = "hyper"
version = "=0.14.4"
features = ["full"]

Then run cargo miri run, and then run the same command again.

Expected behavior: the second time, the program is being run immediately.

Actual behavior: hyper is being rebuilt, as the build log shows:

$ cargo +miri miri run
   Compiling hyper v0.14.4
   Compiling playground v0.0.1 (/home/r/src/rust/rust-playground/playground)
    Finished dev [unoptimized + debuginfo] target(s) in 4.29s
     Running `/home/r/.cargo/bin/cargo-miri target/x86_64-unknown-linux-gnu/debug/playground`
Hello, world!

[RalfJung]

hyper is built with the flags --crate-type lib --crate-type staticlib --crate-type cdylib. I suspect that this is caused by not removing --crate-type any more, and cargo then noticing a missing output file and doing a rebuild of the crate. So we probably should either add back the --crate-type removal or create more "fake output files". Cc @hyd-dev

EDIT: Oh, filtering this out makes no sense. The problem is cargo expecting certain files to be created, changing the flags will not fix that.