message: we no longer need to mess with the environment in our test suite
diff: @@ -8,7 +8,6 @@ use colored::*;
  use std::slice::SliceConcatExt;
  use std::path::{PathBuf, Path};
  use std::io::Write;
  -use std::env;
  macro_rules! eprintln {
  ($($arg:tt)*) => {
  @@ -111,9 +110,6 @@ fn miri_pass(sysroot: &Path, path: &str, target: &str, host: &str, need_fullmir:
  // For now, only validate without optimizations. Inlining breaks validation.
  flags.push("-Zmir-emit-validate=1".to_owned());
  }
  - // Control miri logging. This is okay despite concurrent test execution as all tests
  - // will set this env var to the same value.
  - env::set_var("MIRI_LOG", "warn");
  config.target_rustcflags = Some(flags.join(" "));
  compiletest::run_tests(&config);
  }
  