Test IO error resilience while walking directories

Remove `build_script::build_script_scan_eacces`  test case because cargo
ignores it and returns its path during a `cargo build`. The caller still
has a chance to hit the IO error if they does access it.

tests/testsuite/build.rs

@@ -1687,7 +1687,11 @@ fn ignore_broken_symlinks() {
         .symlink_dir("a/b", "a/b/c/d/foo")
         .build();
 
-    p.cargo("build").run();
+    p.cargo("build")
+        .with_stderr_contains(
+            "[WARNING] File system loop found: [..]/a/b/c/d/foo points to an ancestor [..]/a/b",
+        )
+        .run();
     assert!(p.bin("foo").is_file());
 
     p.process(&p.bin("foo")).with_stdout("i am foo\n").run();

tests/testsuite/build_script.rs

@@ -4618,75 +4618,6 @@ fn links_interrupted_can_restart() {
         .run();
 }
 
-#[cargo_test]
-#[cfg(unix)]
-fn build_script_scan_eacces() {
-    // build.rs causes a scan of the whole project, which can be a problem if
-    // a directory is not accessible.
-    use cargo_test_support::git;
-    use std::os::unix::fs::PermissionsExt;
-
-    let p = project()
-        .file("src/lib.rs", "")
-        .file("build.rs", "fn main() {}")
-        .file("secrets/stuff", "")
-        .build();
-    let path = p.root().join("secrets");
-    fs::set_permissions(&path, fs::Permissions::from_mode(0o0)).unwrap();
-    // The last "Caused by" is a string from libc such as the following:
-    //   Permission denied (os error 13)
-    p.cargo("build")
-        .with_stderr(
-            "\
-[ERROR] failed to determine package fingerprint for build script for foo v0.0.1 ([..]/foo)
-An I/O error happened[..]
-
-By default[..]
-it to[..]
-file[..]
-See[..]
-
-Caused by:
-  failed to determine the most recently modified file in [..]/foo
-
-Caused by:
-  failed to determine list of files in [..]/foo
-
-Caused by:
-  IO error for operation on [..]/foo/secrets: [..]
-
-Caused by:
-  [..]
-",
-        )
-        .with_status(101)
-        .run();
-
-    // Try `package.exclude` to skip a directory.
-    p.change_file(
-        "Cargo.toml",
-        r#"
-        [package]
-        name = "foo"
-        version = "0.0.1"
-        exclude = ["secrets"]
-        "#,
-    );
-    p.cargo("build").run();
-
-    // Try with git. This succeeds because the git status walker ignores
-    // directories it can't access.
-    p.change_file("Cargo.toml", &basic_manifest("foo", "0.0.1"));
-    p.build_dir().rm_rf();
-    let repo = git::init(&p.root());
-    git::add(&repo);
-    git::commit(&repo);
-    p.cargo("build").run();
-
-    // Restore permissions so that the directory can be deleted.
-    fs::set_permissions(&path, fs::Permissions::from_mode(0o755)).unwrap();
-}
-
 #[cargo_test]
 fn dev_dep_with_links() {
     let p = project()

tests/testsuite/package.rs

@@ -794,10 +794,10 @@ fn broken_symlink() {
         .with_status(101)
         .with_stderr_contains(
             "\
-error: failed to determine list of files [..]/foo
+[ERROR] failed to prepare local package for uploading
 
 Caused by:
-  IO error for operation on [..]/foo/src/foo.rs: [..]
+  failed to open for archiving: `[..]foo.rs`
 
 Caused by:
   [..]
@@ -841,9 +841,8 @@ fn filesystem_loop() {
         .symlink_dir("a/b", "a/b/c/d/foo")
         .build()
         .cargo("package -v")
-        .with_status(101)
         .with_stderr_contains(
-            "  File system loop found: [..]/a/b/c/d/foo points to an ancestor [..]/a/b",
+            "[WARNING] File system loop found: [..]/a/b/c/d/foo points to an ancestor [..]/a/b",
         )
         .run();
 }