```
error[E0277]: the trait bound `dep_2_reexport::Type: Trait` is not satisfied because the trait comes from a different crate version
--> multiple-dep-versions.rs:7:18
|
7 | do_something(Type);
| ^^^^ the trait `Trait` is not implemented for `dep_2_reexport::Type`
|
note: there are multiple different versions of crate `dependency` in the dependency graph
--> /home/gh-estebank/rust/build/x86_64-unknown-linux-gnu/test/run-make/crate-loading/rmake_out/multiple-dep-versions-1.rs:4:1
|
3 | pub struct Type(pub i32);
| --------------- this type implements the required trait
4 | pub trait Trait {
| ^^^^^^^^^^^^^^^ this is the required trait
|
::: multiple-dep-versions.rs:1:1
|
1 | extern crate dep_2_reexport;
| ---------------------------- one version of crate `dependency` is used here, as a dependency of crate `foo`
2 | extern crate dependency;
| ------------------------ one version of crate `dependency` is used here, as a direct dependency of the current crate
|
::: /home/gh-estebank/rust/build/x86_64-unknown-linux-gnu/test/run-make/crate-loading/rmake_out/multiple-dep-versions-2.rs:3:1
|
3 | pub struct Type;
| --------------- this type doesn't implement the required trait
4 | pub trait Trait {
| --------------- this is the found trait
= note: two types coming from two different versions of the same crate are different types even if they look the same
= help: you can use `cargo tree` to explore your dependency tree
```
The approach to accomplish this is a HACK, and we'd want a better way to do this. I believe that moving E0277 to be a structured diagnostic would help in that regard.
The run-make test suite contains tests which are the most flexible out of all
the rust-lang/rust test suites. run-make
tests can basically contain arbitrary code, and are supported by the
run_make_support library.
Infrastructure
There are two kinds of run-make tests:
The new rmake.rs version: this allows run-make tests to be written in Rust
(with rmake.rs as the main test file).
The legacy Makefile version: this is what run-make tests were written with
before support for rmake.rs was introduced.
The implementation for collecting and building the rmake.rs recipes (or
Makefiles) are in
src/tools/compiletest/src/runtest.rs,
in run_rmake_v2_test and run_rmake_legacy_test.
Rust-based run-make tests: rmake.rs
The setup for the rmake.rs version is a 3-stage process:
First, we build the run_make_support library in bootstrap as a tool lib.
Then, we compile the rmake.rs "recipe" linking the support library and its
dependencies in, and provide a bunch of env vars. We setup a directory
structure within build/<target>/test/run-make/
<test-name>/
rmake.exe # recipe binary
rmake_out/ # sources from test sources copied over
and copy non-rmake.rs input support files over to rmake_out/. The
support library is made available as an extern prelude.
Finally, we run the recipe binary and set rmake_out/ as the working
directory.
Formatting
Note that files under tests/ are not formatted by ./x fmt,
use rustfmt tests/path/to/file.rs to format a specific file if desired.