message: Switch to exhaustive matches in tests.
diff: @@ -1531,7 +1531,7 @@ fn self_dependency() {
  .build();
  assert_that(p.cargo("build"),
  execs().with_status(101)
  - .with_stderr_contains("\
  + .with_stderr("\
  [ERROR] cyclic package dependency: package `test v0.0.0 ([..])` depends on itself. Cycle:
  package `test v0.0.0 ([..]foo)`"));
  }
  @@ -2652,7 +2652,7 @@ fn cyclic_deps_rejected() {
  assert_that(p.cargo("build").arg("-v"),
  execs().with_status(101)
  - .with_stderr_contains(
  + .with_stderr(
  r#"[ERROR] cyclic package dependency: package `a v0.0.1 ([..])` depends on itself. Cycle:
  package `a v0.0.1 ([..]a)`
  ... which is depended on by `foo v0.0.1 ([..]foo)`[..]"#));
  