Make miri easier to install

[RalfJung]

It would be great if we could make miri easier to install.

miri + cargo miri

One thing is getting miri (and cargo-miri) itself. The ideal solution here would be making this a component in rustup so that it comes with a matching nightly. The dev-tools team has said they would support us in getting that done, after the edition.

libstd

However, miri isn't extremely useful if libstd comes without all the MIR. Right now, I don't think just making it a component is going to do much good, if people still have to then clone our repo to run xargo/build.sh.

The best I can think of here is to do this automatically in miri itself: Basically, to move xargo/* into the miri library, and have a setup step in the beginning which automatically compiles and then uses an appropriate libstd. Sounds rather hacky, but does anyone have a better idea?

[RalfJung]

The second item above is solved: cargo miri now automatically installs and uses xargo.

What remains is distributing miri itself. @oli-obk you have some experience with clippy, can you help making miri a rustup component?

[oli-obk]

I'll do it over the holidays. I'll want to deduplicate some work between e.g. clippy and miri distribution instead of just copypasting everything.

[RalfJung]

Sounds great :)

[RalfJung]

@oli-obk what is the state of making Miri a rustup component?

[mati865]

I believe it should be available with next release of rustup (or with git checkout).

[RalfJung]

I thought rustup needs patching to hook cargo-miri, or so?

[mati865]

You mean rust-lang/rustup#1606?

[RalfJung]

Ah, I didn't know that already landed!

Whom should we bug for a rustup release?

[mati865]

Most of the releases were made by alexcrichton, Idk about the preferred way to contact.

[RalfJung]

@alexcrichton When do you usually make rustup releases? Would be nice to get one that includes the Miri support.

[alexcrichton]

It's just on-demand, there's no schedule currently. There's development happening on rustup right now and presumably when that reaches a good point a release can be made.