Include repository name in splicing errors (#3478)

Fixes #3460

Author: illicitonion

crate_universe/extensions.bzl

@@ -638,6 +638,7 @@ def _generate_hub_and_spokes(
             config_path = config_file,
             output_dir = tag_path.get_child("splicing-output"),
             debug_workspace_dir = tag_path.get_child("splicing-workspace"),
+            repository_name = cfg.name,
         )
 
         # If a cargo lockfile was not provided, use the splicing lockfile.

crate_universe/private/crates_repository.bzl

@@ -89,6 +89,7 @@ def _crates_repository_impl(repository_ctx):
             splicing_manifest = splicing_manifest,
             config_path = config_path,
             output_dir = repository_ctx.path("splicing-output"),
+            repository_name = repository_ctx.name,
         )
 
         kwargs.update({

crate_universe/private/splicing_utils.bzl

@@ -122,6 +122,7 @@ def splice_workspace_manifest(
         splicing_manifest,
         config_path,
         output_dir,
+        repository_name,
         debug_workspace_dir = None):
     """Splice together a Cargo workspace from various other manifests and package definitions
 
@@ -132,6 +133,7 @@ def splice_workspace_manifest(
         splicing_manifest (path): The path to a splicing manifest.
         config_path (path): The path to the config file (containing `cargo_bazel::config::Config`.)
         output_dir (path): THe location in which to write splicing outputs.
+        repository_name (str): Name of the repository being generated.
         debug_workspace_dir (path): The location in which to save splicing outputs for future review.
 
     Returns:
@@ -147,6 +149,8 @@ def splice_workspace_manifest(
         splicing_manifest,
         "--config",
         config_path,
+        "--repository-name",
+        repository_name,
     ]
 
     if cargo_lockfile:

crate_universe/src/cli/splice.rs

@@ -57,6 +57,10 @@ pub struct SpliceOptions {
     /// The path to a rustc binary for use with Cargo
     #[clap(long, env = "RUSTC")]
     pub rustc: PathBuf,
+
+    /// The name of the repository being generated.
+    #[clap(long)]
+    pub repository_name: String,
 }
 
 /// Combine a set of disjoint manifests into a single workspace.
@@ -84,7 +88,7 @@ pub fn splice(opt: SpliceOptions) -> Result<()> {
     // Splice together the manifest
     let manifest_path = splicer
         .splice_workspace()
-        .context("Failed to splice workspace")?;
+        .with_context(|| format!("Failed to splice workspace {}", opt.repository_name))?;
 
     // Generate a lockfile
     let cargo_lockfile = generate_lockfile(

crate_universe/tests/cargo_integration_test.rs

@@ -116,6 +116,7 @@ fn run(repository_name: &str, manifests: HashMap<String, String>, lockfile: &str
         config,
         cargo,
         rustc,
+        repository_name: String::from("crates_index"),
     })
     .unwrap();