fix(): error context for git_fetch refspec not found

src/cargo/sources/git/utils.rs

@@ -1152,6 +1152,13 @@ pub fn fetch(
                         continue;
                     }
                 }
+                if matches!(err.class(), ErrorClass::Net) && err.code() == git2::ErrorCode::Eof {
+                    let revspec_id: String = refspecs
+                        .iter()
+                        .map(|s| s.split(':').next().unwrap_or("").to_string())
+                        .collect();
+                    return Err(anyhow!("refspec {revspec_id} not found on {remote_url}"));
+                }
 
                 return Err(err.into());
             }
@@ -1221,9 +1228,21 @@ fn fetch_with_cli(
         .env_remove("GIT_OBJECT_DIRECTORY")
         .env_remove("GIT_ALTERNATE_OBJECT_DIRECTORIES")
         .cwd(repo.path());
+
     gctx.shell()
         .verbose(|s| s.status("Running", &cmd.to_string()))?;
-    cmd.exec()?;
+
+    let revspec_id: String = refspecs
+        .iter()
+        .map(|s| s.split(':').next().unwrap_or("").to_string())
+        .collect();
+
+    cmd.exec().with_context(|| {
+        format!(
+            "Failed to fetch via Github fast path \nrevspec {:?} not found",
+            revspec_id
+        )
+    })?;
     Ok(())
 }
 

tests/testsuite/git.rs

@@ -4052,6 +4052,90 @@ src/lib.rs
         .run();
 }
 
+#[cargo_test(public_network_test)]
+fn github_fastpath_error_message() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2015"
+
+                [dependencies]
+                bitflags = { git = "https://github.com/rust-lang/bitflags.git", rev="11111b376b93484341c68fbca3ca110ae5cd2790" }
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+    p.cargo("fetch")
+        .env("CARGO_NET_GIT_FETCH_WITH_CLI", "true")
+        .with_status(101)
+        .with_stderr_data(str![[r#"
+[UPDATING] git repository `https://github.com/rust-lang/bitflags.git`
+fatal: remote [ERROR] upload-pack: not our ref 11111b376b93484341c68fbca3ca110ae5cd2790
+[ERROR] failed to get `bitflags` as a dependency of package `foo v0.1.0 ([ROOT]/foo)`
+
+Caused by:
+  failed to load source for dependency `bitflags`
+
+Caused by:
+  Unable to update https://github.com/rust-lang/bitflags.git?rev=11111b376b93484341c68fbca3ca110ae5cd2790
+
+Caused by:
+  failed to clone into: [ROOT]/home/.cargo/git/db/bitflags-[HASH]
+
+Caused by:
+  Failed to fetch via Github fast path 
+  revspec "+11111b376b93484341c68fbca3ca110ae5cd2790" not found
+
+Caused by:
+  process didn't exit successfully: `git fetch --no-tags --force --update-head-ok 'https://github.com/rust-lang/bitflags.git' '+11111b376b93484341c68fbca3ca110ae5cd2790:refs/commit/11111b376b93484341c68fbca3ca110ae5cd2790'` ([EXIT_STATUS]: 128)
+
+"#]])
+        .run();
+}
+
+#[cargo_test]
+fn git_fetch_cli_false() {
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.1.0"
+                edition = "2015"
+
+                [dependencies]
+                bitflags = { git = "https://github.com/rust-lang/bitflags.git", rev="11111b376b93484341c68fbca3ca110ae5cd2790" }
+            "#,
+        )
+        .file("src/lib.rs", "")
+        .build();
+    p.cargo("fetch")
+        .with_status(101)
+        .with_stderr_data(str![[r#"
+[UPDATING] git repository `https://github.com/rust-lang/bitflags.git`
+[ERROR] failed to get `bitflags` as a dependency of package `foo v0.1.0 ([ROOT]/foo)`
+
+Caused by:
+  failed to load source for dependency `bitflags`
+
+Caused by:
+  Unable to update https://github.com/rust-lang/bitflags.git?rev=11111b376b93484341c68fbca3ca110ae5cd2790
+
+Caused by:
+  failed to clone into: [ROOT]/home/.cargo/git/db/bitflags-[HASH]
+
+Caused by:
+  refspec +11111b376b93484341c68fbca3ca110ae5cd2790 not found on https://github.com/rust-lang/bitflags.git
+
+"#]])
+        .run();
+}
+
 #[cargo_test]
 fn git_worktree_with_bare_original_repo() {
     let project = project().build();