Handle case-colliding artifact extraction failures on macOS without aborting remaining downloads

pkg/cli/logs_download.go

@@ -477,7 +477,16 @@ func listArtifacts(outputDir string) ([]string, error) {
 // failing the entire download.
 func isNonZipArtifactError(output []byte) bool {
 	s := string(output)
-	return strings.Contains(s, "zip: not a valid zip file") || strings.Contains(s, "error extracting zip archive")
+	return strings.Contains(s, "zip: not a valid zip file")
+}
+
+// isCaseCollisionArtifactError reports whether gh run download failed because
+// a zip extraction attempted to write a file that already exists. This can
+// happen on case-insensitive filesystems (e.g. macOS) when an artifact
+// contains files whose names differ only by case.
+func isCaseCollisionArtifactError(output []byte) bool {
+	s := string(output)
+	return strings.Contains(s, "error extracting zip archive") && strings.Contains(s, "file exists")
 }
 
 // isDockerBuildArtifact reports whether an artifact name represents a .dockerbuild artifact.
@@ -754,6 +763,9 @@ func downloadRunArtifacts(ctx context.Context, runID int64, outputDir string, ve
 		// skippedNonZipArtifacts is set when gh run download fails due to non-zip artifacts
 		// that were not detected during the listing phase (e.g., listing failed).
 		var skippedNonZipArtifacts bool
+		// skippedCaseCollisionArtifacts is set when gh run download fails because a single
+		// artifact contains case-colliding paths on case-insensitive filesystems.
+		var skippedCaseCollisionArtifacts bool
 
 		if err != nil {
 			// Stop spinner on error
@@ -799,6 +811,9 @@ func downloadRunArtifacts(ctx context.Context, runID int64, outputDir string, ve
 				}
 				fmt.Fprintln(os.Stderr, console.FormatWarningMessage("Some artifacts could not be extracted (not a valid zip archive) and were skipped: "+msg))
 				skippedNonZipArtifacts = true
+			} else if isCaseCollisionArtifactError(output) {
+				fmt.Fprintln(os.Stderr, console.FormatWarningMessage("Some artifacts could not be fully extracted due to case-colliding file paths. Retrying artifacts individually and continuing."))
+				skippedCaseCollisionArtifacts = true
 			} else {
 				return fmt.Errorf("failed to download artifacts for run %d: %w (output: %s)", runID, err, string(output))
 			}
@@ -811,6 +826,33 @@ func downloadRunArtifacts(ctx context.Context, runID int64, outputDir string, ve
 			retryCriticalArtifacts(ctx, runID, outputDir, verbose, owner, repo, hostname, artifactFilter)
 		}
 
+		// When bulk download fails on case-colliding entries, gh CLI aborts and may skip
+		// artifacts that appear later in the run. Retry artifacts individually so one bad
+		// artifact does not block the rest.
+		if skippedCaseCollisionArtifacts {
+			retryNames := downloadableNames
+			if len(retryNames) == 0 {
+				// Initial artifact listing was unavailable, so fetch names now for targeted retry.
+				artifactNamesRetry, retryListErr := listRunArtifactNames(ctx, runID, owner, repo, hostname, verbose)
+				if retryListErr != nil {
+					return fmt.Errorf("bulk artifact download hit case-colliding entries and could not list artifacts for individual retry: %w", retryListErr)
+				}
+				for _, name := range artifactNamesRetry {
+					if isDockerBuildArtifact(name) {
+						continue
+					}
+					if artifactMatchesFilter(name, artifactFilter) {
+						retryNames = append(retryNames, name)
+					}
+				}
+			}
+			if len(retryNames) > 0 {
+				if err := downloadArtifactsByName(ctx, runID, outputDir, retryNames, verbose, owner, repo, hostname); err != nil {
+					return err
+				}
+			}
+		}
+
 		if skippedNonZipArtifacts && fileutil.IsDirEmpty(outputDir) {
 			// All artifacts were non-zip (none could be extracted) so nothing was downloaded.
 			// Treat this the same as a run with no artifacts — the audit will rely solely on

pkg/cli/logs_download_test.go

@@ -130,9 +130,9 @@ func TestIsNonZipArtifactError(t *testing.T) {
 			expected: true,
 		},
 		{
-			name:     "error extracting zip archive",
+			name:     "generic extraction error without zip signature",
 			output:   "error downloading some-artifact: error extracting zip archive: unexpected EOF",
-			expected: true,
+			expected: false,
 		},
 		{
 			name:     "both patterns present",
@@ -166,6 +166,39 @@ func TestIsNonZipArtifactError(t *testing.T) {
 	}
 }
 
+func TestIsCaseCollisionArtifactError(t *testing.T) {
+	tests := []struct {
+		name     string
+		output   string
+		expected bool
+	}{
+		{
+			name:     "case-collision file exists error",
+			output:   "error downloading repo-memory-default: error extracting zip archive: error extracting \"memory.md\": open /tmp/artifacts/repo-memory-default/memory.md: file exists",
+			expected: true,
+		},
+		{
+			name:     "generic extraction error without file exists",
+			output:   "error downloading some-artifact: error extracting zip archive: unexpected EOF",
+			expected: false,
+		},
+		{
+			name:     "file exists without extraction context",
+			output:   "open /tmp/out/file.txt: file exists",
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isCaseCollisionArtifactError([]byte(tt.output))
+			if result != tt.expected {
+				t.Errorf("isCaseCollisionArtifactError(%q) = %v, want %v", tt.output, result, tt.expected)
+			}
+		})
+	}
+}
+
 func TestIsDockerBuildArtifact(t *testing.T) {
 	tests := []struct {
 		name     string