Log action errors for build directory cleanup

There was no error reporting for failure to clean up the build
directories and this would fail creation of the same action the next
time it is executed. This is an unexpected error and we have not needed
it before, but on Windows some files may be locked. We cannot return an
error to the client, as it may retry the action and then fail directory
creation, and keep retrying.

pkg/builder/local_build_executor.go

@@ -2,6 +2,7 @@ package builder
 
 import (
 	"context"
+	"log"
 	"os"
 	"sync"
 	"time"
@@ -125,9 +126,9 @@ func (be *localBuildExecutor) CheckReadiness(ctx context.Context) error {
 	return err
 }
 
-func (be *localBuildExecutor) Execute(ctx context.Context, filePool re_filesystem.FilePool, monitor access.UnreadDirectoryMonitor, digestFunction digest.Function, request *remoteworker.DesiredState_Executing, executionStateUpdates chan<- *remoteworker.CurrentState_Executing) *remoteexecution.ExecuteResponse {
+func (be *localBuildExecutor) Execute(ctx context.Context, filePool re_filesystem.FilePool, monitor access.UnreadDirectoryMonitor, digestFunction digest.Function, request *remoteworker.DesiredState_Executing, executionStateUpdates chan<- *remoteworker.CurrentState_Executing) (response *remoteexecution.ExecuteResponse) {
 	// Timeout handling.
-	response := NewDefaultExecuteResponse(request)
+	response = NewDefaultExecuteResponse(request)
 	action := request.Action
 	if action == nil {
 		attachErrorToExecuteResponse(response, status.Error(codes.InvalidArgument, "Request does not contain an action"))
@@ -158,7 +159,12 @@ func (be *localBuildExecutor) Execute(ctx context.Context, filePool re_filesyste
 			util.StatusWrap(err, "Failed to acquire build environment"))
 		return response
 	}
-	defer buildDirectory.Close()
+	defer func() {
+		err := buildDirectory.Close()
+		if err != nil {
+			log.Printf("Failed to clean up build environment: %v\n", err)
+		}
+	}()
 
 	// Install hooks on build directory to capture file creation and
 	// I/O error events.