repository: Capture stderr on CreateForkcreate_fork_errors

CreateFork had been returning unhelpful exit status errors that are too
ambiguous to allow for debugging.

1 files changed, 27 insertions, 18 deletions

diff --git a/internal/gitaly/service/repository/create_fork.go b/internal/gitaly/service/repository/create_fork.go
index ea9fd3949..7566a9344 100644
--- a/internal/gitaly/service/repository/create_fork.go
+++ b/internal/gitaly/service/repository/create_fork.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"strings"
 
 	"gitlab.com/gitlab-org/gitaly/v15/internal/git"
 	"gitlab.com/gitlab-org/gitaly/v15/internal/helper"
@@ -38,30 +39,38 @@ func (s *server) CreateFork(ctx context.Context, req *gitalypb.CreateForkRequest
 		// Ideally we'd just fetch into the already-created repo, but that wouldn't
 		// allow us to easily set up HEAD to point to the correct ref. We thus have
 		// no easy choice but to use git-clone(1).
-		cmd, err := s.gitCmdFactory.NewWithoutRepo(ctx, git.SubCmd{
-			Name: "clone",
-			Flags: []git.Option{
-				git.Flag{Name: "--bare"},
+		var stderr strings.Builder
+		cmd, err := s.gitCmdFactory.NewWithoutRepo(ctx,
+			git.SubCmd{
+				Name: "clone",
+				Flags: []git.Option{
+					git.Flag{Name: "--bare"},
+					git.Flag{Name: "--quiet"},
+				},
+				Args: []string{
+					git.InternalGitalyURL,
+					targetPath,
+				},
 			},
-			Args: []string{
-				git.InternalGitalyURL,
-				targetPath,
-			},
-		}, git.WithInternalFetch(&gitalypb.SSHUploadPackRequest{
-			Repository: sourceRepository,
-		}), git.WithConfig(git.ConfigPair{
-			// Disable consistency checks for fetched objects when creating a
-			// fork. We don't want to end up in a situation where it's
-			// impossible to create forks we already have anyway because we have
-			// e.g. retroactively tightened the consistency checks.
-			Key: "fetch.fsckObjects", Value: "false",
-		}), git.WithDisabledHooks())
+			git.WithInternalFetch(&gitalypb.SSHUploadPackRequest{
+				Repository: sourceRepository,
+			}),
+			git.WithConfig(git.ConfigPair{
+				// Disable consistency checks for fetched objects when creating a
+				// fork. We don't want to end up in a situation where it's
+				// impossible to create forks we already have anyway because we have
+				// e.g. retroactively tightened the consistency checks.
+				Key: "fetch.fsckObjects", Value: "false",
+			}),
+			git.WithDisabledHooks(),
+			git.WithStderr(&stderr),
+		)
 		if err != nil {
 			return fmt.Errorf("spawning fetch: %w", err)
 		}
 
 		if err := cmd.Wait(); err != nil {
-			return fmt.Errorf("fetching source repo: %w", err)
+			return fmt.Errorf("fetching source repo: %w, stderr: %q", err, stderr.String())
 		}
 
 		if err := s.removeOriginInRepo(ctx, repo); err != nil {