Updates to path source walking.

src/cargo/core/compiler/fingerprint.rs

@@ -1209,7 +1209,12 @@ fn calculate_normal(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Finger
     let target_root = target_root(cx);
     let local = if unit.mode.is_doc() {
         // rustdoc does not have dep-info files.
-        let fingerprint = pkg_fingerprint(cx.bcx, &unit.pkg)?;
+        let fingerprint = pkg_fingerprint(cx.bcx, &unit.pkg).chain_err(|| {
+            format!(
+                "failed to determine package fingerprint for documenting {}",
+                unit.pkg
+            )
+        })?;
         vec![LocalFingerprint::Precalculated(fingerprint)]
     } else {
         let dep_info = dep_info_loc(cx, unit);
@@ -1270,7 +1275,18 @@ fn calculate_run_custom_build(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoRes
     // the whole crate.
     let (gen_local, overridden) = build_script_local_fingerprints(cx, unit);
     let deps = &cx.build_explicit_deps[unit];
-    let local = (gen_local)(deps, Some(&|| pkg_fingerprint(cx.bcx, &unit.pkg)))?.unwrap();
+    let local = (gen_local)(
+        deps,
+        Some(&|| {
+            pkg_fingerprint(cx.bcx, &unit.pkg).chain_err(|| {
+                format!(
+                    "failed to determine package fingerprint for build script for {}",
+                    unit.pkg
+                )
+            })
+        }),
+    )?
+    .unwrap();
     let output = deps.build_script_output.clone();
 
     // Include any dependencies of our execution, which is typically just the

src/cargo/sources/path.rs

@@ -96,6 +96,15 @@ impl<'cfg> PathSource<'cfg> {
     /// are relevant for building this package, but it also contains logic to
     /// use other methods like .gitignore to filter the list of files.
     pub fn list_files(&self, pkg: &Package) -> CargoResult<Vec<PathBuf>> {
+        self._list_files(pkg).chain_err(|| {
+            format!(
+                "failed to determine list of files in {}",
+                pkg.root().display()
+            )
+        })
+    }
+
+    fn _list_files(&self, pkg: &Package) -> CargoResult<Vec<PathBuf>> {
         let root = pkg.root();
         let no_include_option = pkg.manifest().include().is_empty();
 
@@ -111,17 +120,21 @@ impl<'cfg> PathSource<'cfg> {
         }
         let ignore_include = include_builder.build()?;
 
-        let ignore_should_package = |relative_path: &Path| -> CargoResult<bool> {
+        let ignore_should_package = |relative_path: &Path, is_dir: bool| -> CargoResult<bool> {
             // "Include" and "exclude" options are mutually exclusive.
             if no_include_option {
-                match ignore_exclude
-                    .matched_path_or_any_parents(relative_path, /* is_dir */ false)
-                {
+                match ignore_exclude.matched_path_or_any_parents(relative_path, is_dir) {
                     Match::None => Ok(true),
                     Match::Ignore(_) => Ok(false),
                     Match::Whitelist(_) => Ok(true),
                 }
             } else {
+                if is_dir {
+                    // Generally, include directives don't list every
+                    // directory (nor should they!). Just skip all directory
+                    // checks, and only check files.
+                    return Ok(true);
+                }
                 match ignore_include
                     .matched_path_or_any_parents(relative_path, /* is_dir */ false)
                 {
@@ -132,7 +145,7 @@ impl<'cfg> PathSource<'cfg> {
             }
         };
 
-        let mut filter = |path: &Path| -> CargoResult<bool> {
+        let mut filter = |path: &Path, is_dir: bool| -> CargoResult<bool> {
             let relative_path = path.strip_prefix(root)?;
 
             let rel = relative_path.as_os_str();
@@ -142,13 +155,13 @@ impl<'cfg> PathSource<'cfg> {
                 return Ok(true);
             }
 
-            ignore_should_package(relative_path)
+            ignore_should_package(relative_path, is_dir)
         };
 
         // Attempt Git-prepopulate only if no `include` (see rust-lang/cargo#4135).
         if no_include_option {
-            if let Some(result) = self.discover_git_and_list_files(pkg, root, &mut filter) {
-                return result;
+            if let Some(result) = self.discover_git_and_list_files(pkg, root, &mut filter)? {
+                return Ok(result);
             }
             // no include option and not git repo discovered (see rust-lang/cargo#7183).
             return self.list_files_walk_except_dot_files_and_dirs(pkg, &mut filter);
@@ -162,50 +175,52 @@ impl<'cfg> PathSource<'cfg> {
         &self,
         pkg: &Package,
         root: &Path,
-        filter: &mut dyn FnMut(&Path) -> CargoResult<bool>,
-    ) -> Option<CargoResult<Vec<PathBuf>>> {
-        // If this package is in a Git repository, then we really do want to
-        // query the Git repository as it takes into account items such as
-        // `.gitignore`. We're not quite sure where the Git repository is,
-        // however, so we do a bit of a probe.
-        //
-        // We walk this package's path upwards and look for a sibling
-        // `Cargo.toml` and `.git` directory. If we find one then we assume that
-        // we're part of that repository.
-        let mut cur = root;
-        loop {
-            if cur.join("Cargo.toml").is_file() {
-                // If we find a Git repository next to this `Cargo.toml`, we still
-                // check to see if we are indeed part of the index. If not, then
-                // this is likely an unrelated Git repo, so keep going.
-                if let Ok(repo) = git2::Repository::open(cur) {
-                    let index = match repo.index() {
-                        Ok(index) => index,
-                        Err(err) => return Some(Err(err.into())),
-                    };
-                    let path = root.strip_prefix(cur).unwrap().join("Cargo.toml");
-                    if index.get_path(&path, 0).is_some() {
-                        return Some(self.list_files_git(pkg, &repo, filter));
-                    }
-                }
-            }
-            // Don't cross submodule boundaries.
-            if cur.join(".git").is_dir() {
-                break;
-            }
-            match cur.parent() {
-                Some(parent) => cur = parent,
-                None => break,
+        filter: &mut dyn FnMut(&Path, bool) -> CargoResult<bool>,
+    ) -> CargoResult<Option<Vec<PathBuf>>> {
+        let repo = match git2::Repository::discover(root) {
+            Ok(repo) => repo,
+            Err(e) => {
+                log::debug!(
+                    "could not discover git repo at or above {}: {}",
+                    root.display(),
+                    e
+                );
+                return Ok(None);
             }
+        };
+        let index = repo
+            .index()
+            .chain_err(|| format!("failed to open git index at {}", repo.path().display()))?;
+        let repo_root = repo.workdir().ok_or_else(|| {
+            anyhow::format_err!(
+                "did not expect repo at {} to be bare",
+                repo.path().display()
+            )
+        })?;
+        let repo_relative_path = root.strip_prefix(repo_root).chain_err(|| {
+            format!(
+                "expected git repo {} to be parent of package {}",
+                repo.path().display(),
+                root.display()
+            )
+        })?;
+        // Git requires forward-slashes.
+        let repo_safe_path = repo_relative_path
+            .join("Cargo.toml")
+            .to_string_lossy()
+            .replace('\\', "/");
+        if index.get_path(Path::new(&repo_safe_path), 0).is_some() {
+            return Ok(Some(self.list_files_git(pkg, &repo, filter)?));
         }
-        None
+        // Package Cargo.toml is not in git, don't use git to guide our selection.
+        Ok(None)
     }
 
     fn list_files_git(
         &self,
         pkg: &Package,
         repo: &git2::Repository,
-        filter: &mut dyn FnMut(&Path) -> CargoResult<bool>,
+        filter: &mut dyn FnMut(&Path, bool) -> CargoResult<bool>,
     ) -> CargoResult<Vec<PathBuf>> {
         warn!("list_files_git {}", pkg.package_id());
         let index = repo.index()?;
@@ -289,7 +304,10 @@ impl<'cfg> PathSource<'cfg> {
                 continue;
             }
 
-            if is_dir.unwrap_or_else(|| file_path.is_dir()) {
+            // `is_dir` is None for symlinks. The `unwrap` checks if the
+            // symlink points to a directory.
+            let is_dir = is_dir.unwrap_or_else(|| file_path.is_dir());
+            if is_dir {
                 warn!("  found submodule {}", file_path.display());
                 let rel = file_path.strip_prefix(root)?;
                 let rel = rel.to_str().ok_or_else(|| {
@@ -307,7 +325,8 @@ impl<'cfg> PathSource<'cfg> {
                         PathSource::walk(&file_path, &mut ret, false, filter)?;
                     }
                 }
-            } else if (*filter)(&file_path)? {
+            } else if (*filter)(&file_path, is_dir)? {
+                assert!(!is_dir);
                 // We found a file!
                 warn!("  found {}", file_path.display());
                 ret.push(file_path);
@@ -338,29 +357,28 @@ impl<'cfg> PathSource<'cfg> {
     fn list_files_walk_except_dot_files_and_dirs(
         &self,
         pkg: &Package,
-        filter: &mut dyn FnMut(&Path) -> CargoResult<bool>,
+        filter: &mut dyn FnMut(&Path, bool) -> CargoResult<bool>,
     ) -> CargoResult<Vec<PathBuf>> {
         let root = pkg.root();
         let mut exclude_dot_files_dir_builder = GitignoreBuilder::new(root);
         exclude_dot_files_dir_builder.add_line(None, ".*")?;
         let ignore_dot_files_and_dirs = exclude_dot_files_dir_builder.build()?;
 
-        let mut filter_ignore_dot_files_and_dirs = |path: &Path| -> CargoResult<bool> {
-            let relative_path = path.strip_prefix(root)?;
-            match ignore_dot_files_and_dirs
-                .matched_path_or_any_parents(relative_path, /* is_dir */ false)
-            {
-                Match::Ignore(_) => Ok(false),
-                _ => filter(path),
-            }
-        };
+        let mut filter_ignore_dot_files_and_dirs =
+            |path: &Path, is_dir: bool| -> CargoResult<bool> {
+                let relative_path = path.strip_prefix(root)?;
+                match ignore_dot_files_and_dirs.matched_path_or_any_parents(relative_path, is_dir) {
+                    Match::Ignore(_) => Ok(false),
+                    _ => filter(path, is_dir),
+                }
+            };
         self.list_files_walk(pkg, &mut filter_ignore_dot_files_and_dirs)
     }
 
     fn list_files_walk(
         &self,
         pkg: &Package,
-        filter: &mut dyn FnMut(&Path) -> CargoResult<bool>,
+        filter: &mut dyn FnMut(&Path, bool) -> CargoResult<bool>,
     ) -> CargoResult<Vec<PathBuf>> {
         let mut ret = Vec::new();
         PathSource::walk(pkg.root(), &mut ret, true, filter)?;
@@ -371,12 +389,14 @@ impl<'cfg> PathSource<'cfg> {
         path: &Path,
         ret: &mut Vec<PathBuf>,
         is_root: bool,
-        filter: &mut dyn FnMut(&Path) -> CargoResult<bool>,
+        filter: &mut dyn FnMut(&Path, bool) -> CargoResult<bool>,
     ) -> CargoResult<()> {
-        if !path.is_dir() {
-            if (*filter)(path)? {
-                ret.push(path.to_path_buf());
-            }
+        let is_dir = path.is_dir();
+        if !is_root && !(*filter)(path, is_dir)? {
+            return Ok(());
+        }
+        if !is_dir {
+            ret.push(path.to_path_buf());
             return Ok(());
         }
         // Don't recurse into any sub-packages that we have.
@@ -415,7 +435,12 @@ impl<'cfg> PathSource<'cfg> {
 
         let mut max = FileTime::zero();
         let mut max_path = PathBuf::new();
-        for file in self.list_files(pkg)? {
+        for file in self.list_files(pkg).chain_err(|| {
+            format!(
+                "failed to determine the most recently modified file in {}",
+                pkg.root().display()
+            )
+        })? {
             // An `fs::stat` error here is either because path is a
             // broken symlink, a permissions error, or a race
             // condition where this path was `rm`-ed -- either way,

tests/testsuite/build_script.rs

@@ -3977,26 +3977,60 @@ fn links_interrupted_can_restart() {
 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(0)).unwrap();
-    // "Caused by" is a string from libc such as the following:
+    // The last "Caused by" is a string from libc such as the following:
     //   Permission denied (os error 13)
     p.cargo("build")
         .with_stderr(
             "\
-[ERROR] cannot read \"[..]/foo/secrets\"
+[ERROR] failed to determine package fingerprint for build script for foo v0.0.1 ([..]/foo)
+
+Caused by:
+  failed to determine the most recently modified file in [..]/foo
+
+Caused by:
+  failed to determine list of files in [..]/foo
+
+Caused by:
+  cannot read \"[..]/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();
 }