Fix Process output capture re: working_directory. (#12197)

Previously our local Process output capturing did not match the REAPI
spec which led to local execution working and remote execution failing
whenever a Process execution used both `working_directory` and output
capturing.

Add a test that output capturing occurs relative to the
`working_directory` when set and fix out one combined use of
`working_directory` and output capturing in `archive.py`.

Fixes #12157

src/python/pants/core/util_rules/archive.py

@@ -7,7 +7,7 @@
 from dataclasses import dataclass
 from enum import Enum
 
-from pants.engine.fs import CreateDigest, Digest, Directory, MergeDigests, RemovePrefix, Snapshot
+from pants.engine.fs import CreateDigest, Digest, Directory, MergeDigests, Snapshot
 from pants.engine.process import (
     BinaryNotFoundError,
     BinaryPath,
@@ -170,10 +170,10 @@ async def maybe_extract_archive(
     digest: Digest, tar_binary: TarBinary, unzip_binary: UnzipBinary
 ) -> ExtractedArchive:
     """If digest contains a single archive file, extract it, otherwise return the input digest."""
-    output_dir = "__output"
+    extract_archive_dir = "__extract_archive_dir"
     snapshot, output_dir_digest = await MultiGet(
         Get(Snapshot, Digest, digest),
-        Get(Digest, CreateDigest([Directory(output_dir)])),
+        Get(Digest, CreateDigest([Directory(extract_archive_dir)])),
     )
     if len(snapshot.files) != 1:
         return ExtractedArchive(digest)
@@ -199,12 +199,11 @@ async def maybe_extract_archive(
             input_digest=input_digest,
             description=f"Extract {fp}",
             level=LogLevel.DEBUG,
-            output_directories=(output_dir,),
-            working_directory=output_dir,
+            output_directories=(".",),
+            working_directory=extract_archive_dir,
         ),
     )
-    strip_output_dir = await Get(Digest, RemovePrefix(result.output_digest, output_dir))
-    return ExtractedArchive(strip_output_dir)
+    return ExtractedArchive(result.output_digest)
 
 
 def rules():

src/python/pants/engine/process.py

@@ -94,21 +94,24 @@ def __init__(
         that are not explicitly populated. For example, $PATH will not be defined by default, unless
         populated through the `env` parameter.
 
-        Usually, you will want to provide input files/directories via the parameter `input_digest`. The
-        process will then be able to access these paths through relative paths. If you want to give
-        multiple input digests, first merge them with `await Get(Digest, MergeDigests)`.
+        Usually, you will want to provide input files/directories via the parameter `input_digest`.
+        The process will then be able to access these paths through relative paths. If you want to
+        give multiple input digests, first merge them with `await Get(Digest, MergeDigests)`.
 
-        Often, you will want to capture the files/directories created in the process. To do this, you
-        can either set `output_files` or `output_directories`. The specified paths will then be used to
-        populate `output_digest` on the `ProcessResult`. If you want to split up this output digest
-        into multiple digests, use `await Get(Digest, DigestSubset)` on the `output_digest`.
+        Often, you will want to capture the files/directories created in the process. To do this,
+        you can either set `output_files` or `output_directories`. The specified paths should be
+        specified relative to the `working_directory`, if any, and will then be used to populate
+        `output_digest` on the `ProcessResult`. If you want to split up this output digest into
+        multiple digests, use `await Get(Digest, DigestSubset)` on the `output_digest`.
 
         To actually run the process, use `await Get(ProcessResult, Process)` or
         `await Get(FallibleProcessResult, Process)`.
 
         Example:
 
-            result = await Get(ProcessResult, Process(["/bin/echo", "hello world"], description="demo"))
+            result = await Get(
+                ProcessResult, Process(["/bin/echo", "hello world"], description="demo")
+            )
             assert result.stdout == b"hello world"
         """
         if isinstance(argv, str):

src/rust/engine/process_execution/src/local.rs

@@ -80,7 +80,13 @@ impl CommandRunner {
     let output_paths: Result<Vec<String>, String> = output_dir_paths
       .into_iter()
       .flat_map(|p| {
-        let mut dir_glob = PathBuf::from(p).into_os_string();
+        let mut dir_glob = {
+          let mut dir = PathBuf::from(p).into_os_string();
+          if dir.is_empty() {
+            dir.push(".")
+          }
+          dir
+        };
         let dir = dir_glob.clone();
         dir_glob.push("/**");
         vec![dir, dir_glob]
@@ -543,19 +549,21 @@ pub trait CapturedWorkdir {
     let output_snapshot = if req.output_files.is_empty() && req.output_directories.is_empty() {
       store::Snapshot::empty()
     } else {
+      let root = if let Some(ref working_directory) = req.working_directory {
+        workdir_path.join(working_directory)
+      } else {
+        workdir_path.clone()
+      };
       // Use no ignore patterns, because we are looking for explicitly listed paths.
       let posix_fs = Arc::new(
-        fs::PosixFS::new(
-          workdir_path.clone(),
-          fs::GitignoreStyleExcludes::empty(),
-          executor.clone(),
-        )
-        .map_err(|err| {
-          format!(
-            "Error making posix_fs to fetch local process execution output files: {}",
-            err
-          )
-        })?,
+        fs::PosixFS::new(root, fs::GitignoreStyleExcludes::empty(), executor.clone()).map_err(
+          |err| {
+            format!(
+              "Error making posix_fs to fetch local process execution output files: {}",
+              err
+            )
+          },
+        )?,
       );
       CommandRunner::construct_output_snapshot(
         store.clone(),

src/rust/engine/process_execution/src/local_tests.rs

@@ -9,7 +9,7 @@ use hashing::EMPTY_DIGEST;
 use shell_quote::bash;
 use spectral::{assert_that, string::StrAssertions};
 use std;
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, BTreeSet};
 use std::path::PathBuf;
 use std::str;
 use std::time::Duration;
@@ -567,8 +567,8 @@ async fn working_directory() {
   let executor = task_executor::Executor::new();
   let store = Store::local_only(executor.clone(), store_dir.path()).unwrap();
 
-  // Prepare the store to contain /cats/roland.ext, because the EPR needs to materialize it and then run
-  // from the ./cats directory.
+  // Prepare the store to contain /cats/roland.ext, because the EPR needs to materialize it and
+  // then run from the ./cats directory.
   store
     .store_file_bytes(TestData::roland().bytes(), false)
     .await
@@ -586,6 +586,7 @@ async fn working_directory() {
 
   let mut process = Process::new(vec![find_bash(), "-c".to_owned(), "/bin/ls".to_string()]);
   process.working_directory = Some(RelativePath::new("cats").unwrap());
+  process.output_directories = relative_paths(&["roland.ext"]).collect::<BTreeSet<_>>();
   process.input_files = TestDirectory::nested().digest();
   process.timeout = one_second();
   process.description = "confused-cat".to_string();
@@ -603,7 +604,10 @@ async fn working_directory() {
   assert_eq!(result.stdout_bytes, "roland.ext\n".as_bytes());
   assert_eq!(result.stderr_bytes, "".as_bytes());
   assert_eq!(result.original.exit_code, 0);
-  assert_eq!(result.original.output_directory, EMPTY_DIGEST);
+  assert_eq!(
+    result.original.output_directory,
+    TestDirectory::containing_roland().digest()
+  );
   assert_eq!(result.original.platform, Platform::current().unwrap());
 }