Improve io error message context

- include the failed recipe, shell and working directory
- include the original io error message from Command.status()
- include the io error message from read_dir() check if it differs from
  the original

On Unix the two error messages don't differ in the cases that we test,
but we don't want to assume that is always the case.

Additionally test error messages when both workdir and shell are
unusable.

src/error.rs

@@ -116,6 +116,9 @@ pub(crate) enum Error<'src> {
   Io {
     recipe: &'src str,
     io_error: io::Error,
+    shell: String,
+    working_directory_io_error: Option<io::Error>,
+    working_directory: Option<PathBuf>,
   },
   Load {
     path: PathBuf,
@@ -186,11 +189,6 @@ pub(crate) enum Error<'src> {
     justfile: PathBuf,
     io_error: io::Error,
   },
-  WorkingDirectoryIo {
-    recipe: &'src str,
-    working_directory: PathBuf,
-    io_error: io::Error,
-  },
 }
 
 impl<'src> Error<'src> {
@@ -401,12 +399,15 @@ impl<'src> ColorDisplay for Error<'src> {
         write!(f, "Internal runtime error, this may indicate a bug in just: {message} \
                    consider filing an issue: https://github.com/casey/just/issues/new")?;
       }
-      Io { recipe, io_error } => {
-        match io_error.kind() {
-          io::ErrorKind::NotFound => write!(f, "Recipe `{recipe}` could not be run because just could not find the shell: {io_error}"),
-          io::ErrorKind::PermissionDenied => write!(f, "Recipe `{recipe}` could not be run because just could not run the shell: {io_error}"),
-          _ => write!(f, "Recipe `{recipe}` could not be run because of an IO error while launching the shell: {io_error}"),
-        }?;
+      Io { recipe, io_error, shell, working_directory_io_error, working_directory } => {
+        write!(f, "Failed to run recipe `{recipe}`:\n  Failed to run shell `{shell}`:\n    {io_error}", )?;
+        if let Some(working_directory_io_error) = working_directory_io_error {
+          let working_directory = working_directory.as_ref().expect("is Some when error is Some").display();
+          write!(f, "\n  Failed to set working directory to `{working_directory}`")?;
+          if working_directory_io_error.to_string() != io_error.to_string() {
+            write!(f, ":\n    {working_directory_io_error}")?;
+          }
+        }
       }
       Load { io_error, path } => {
         write!(f, "Failed to read justfile at `{}`: {io_error}", path.display())?;
@@ -475,9 +476,6 @@ impl<'src> ColorDisplay for Error<'src> {
       UnstableFeature { unstable_feature } => {
         write!(f, "{unstable_feature} Invoke `just` with `--unstable`, set the `JUST_UNSTABLE` environment variable, or add `set unstable` to your `justfile` to enable unstable features.")?;
       }
-      WorkingDirectoryIo { recipe, working_directory, io_error } => {
-        write!(f, "Recipe `{recipe}` could not be run because just could not set working directory to `{}`: {io_error}", working_directory.display())?;
-      },
       WriteJustfile { justfile, io_error } => {
         let justfile = justfile.display();
         write!(f, "Failed to write justfile to `{justfile}`: {io_error}")?;

src/recipe.rs

@@ -304,18 +304,23 @@ impl<'src, D> Recipe<'src, D> {
           }
         }
         Err(io_error) => {
-          if let Some(working_directory) = self.working_directory(context) {
-            if let Err(io_error) = fs::read_dir(&working_directory) {
-              return Err(Error::WorkingDirectoryIo {
-                recipe: self.name(),
-                working_directory,
-                io_error,
-              });
-            }
-          }
+          let working_directory = self.working_directory(context);
+          let working_directory_io_error = match &working_directory {
+            Some(working_directory) => match fs::read_dir(&working_directory) {
+              Ok(_) => None,
+              Err(io_error) => Some(io_error),
+            },
+            // no working directory = no attempt to change current working directory = no error
+            None => None,
+          };
+          let (shell, _) = context.module.settings.shell(config);
+
           return Err(Error::Io {
             recipe: self.name(),
             io_error,
+            shell: shell.into(),
+            working_directory_io_error,
+            working_directory,
           });
         }
       };

tests/shell.rs

@@ -164,7 +164,7 @@ fn recipe_shell_not_found_error_message() {
     .shell(false)
     .args(["--shell", "NOT_A_REAL_SHELL"])
     .stderr_regex(
-      "error: Recipe `foo` could not be run because just could not find the shell: .*\n",
+      ".*Failed to run recipe `foo`:\n  Failed to run shell `NOT_A_REAL_SHELL`:\n    .*",
     )
     .status(1)
     .run();

tests/working_directory.rs

@@ -343,9 +343,7 @@ fn missing_working_directory_produces_clear_message() {
     ",
     )
     .status(1)
-    .stderr_regex(
-      ".*Recipe `default` could not be run because just could not set working directory to `.*/missing`.*",
-    )
+    .stderr_regex(".*Failed to run recipe `default`:\n  Failed to run shell `bash`:\n    .*\n  Failed to set working directory to `.*/missing`.*")
     .run();
 }
 
@@ -366,9 +364,7 @@ fn unusable_working_directory_produces_clear_message() {
   })
   .chmod("unusable", Permissions::from_mode(0o000))
   .status(1)
-  .stderr_regex(
-    ".*Recipe `default` could not be run because just could not set working directory to `.*/unusable`:.*",
-  )
+  .stderr_regex(".*Failed to run recipe `default`:\n  Failed to run shell `bash`:\n    .*\n  Failed to set working directory to `.*/unusable`.*")
   .run();
 }
 
@@ -386,8 +382,66 @@ fn working_directory_is_not_a_directory_produces_clear_message() {
     unusable: "is not a directory"
   })
   .status(1)
-  .stderr_regex(
-    ".*Recipe `default` could not be run because just could not set working directory to `.*/unusable`:.*",
+  .stderr_regex(".*Failed to run recipe `default`:\n  Failed to run shell `bash`:\n    .*\n  Failed to set working directory to `.*/unusable`.*")
+  .run();
+}
+
+#[test]
+fn missing_working_directory_and_missing_shell_produces_clear_message() {
+  Test::new()
+    .justfile(
+      "
+      set working-directory := 'missing'
+      default:
+        pwd
+    ",
+    )
+    .shell(false)
+    .args(["--shell", "NOT_A_REAL_SHELL"])
+    .status(1)
+    .stderr_regex(".*Failed to run recipe `default`:\n  Failed to run shell `NOT_A_REAL_SHELL`:\n    .*\n  Failed to set working directory to `.*/missing`.*")
+    .run();
+}
+
+#[test]
+#[cfg(unix)]
+fn unusable_working_directory_and_missing_shell_produces_clear_message() {
+  use {fs::Permissions, std::os::unix::fs::PermissionsExt};
+  Test::new()
+  .justfile(
+    "
+    set working-directory := 'unusable'
+    default:
+      pwd
+  ",
+  )
+  .tree(tree! {
+    unusable: {}
+  })
+  .shell(false)
+  .args(["--shell", "NOT_A_REAL_SHELL"])
+  .chmod("unusable", Permissions::from_mode(0o000))
+  .status(1)
+  .stderr_regex(".*Failed to run recipe `default`:\n  Failed to run shell `NOT_A_REAL_SHELL`:\n    .*\n  Failed to set working directory to `.*/unusable`.*")
+  .run();
+}
+
+#[test]
+fn working_directory_is_not_a_directory_and_missing_shell_produces_clear_message() {
+  Test::new()
+  .justfile(
+    "
+    set working-directory := 'unusable'
+    default:
+      pwd
+  ",
   )
+  .tree(tree! {
+    unusable: "is not a directory"
+  })
+  .shell(false)
+  .args(["--shell", "NOT_A_REAL_SHELL"])
+  .status(1)
+  .stderr_regex(".*Failed to run recipe `default`:\n  Failed to run shell `NOT_A_REAL_SHELL`:\n    .*\n  Failed to set working directory to `.*/unusable`.*")
   .run();
 }