Try to reduce errors when deleting substitute cache files

1 files changed, 13 insertions, 10 deletions

diff --git a/guix-build-coordinator/utils.scm b/guix-build-coordinator/utils.scm
index 3767eef..259e293 100644
--- a/guix-build-coordinator/utils.scm
+++ b/guix-build-coordinator/utils.scm
@@ -301,16 +301,19 @@ upcoming chunk."
                        (string-append
                         %narinfo-cache-directory "/"
                         directory "/" hash-part)))
-                  (when (file-exists? cache-file)
-                    (with-exception-handler
-                        (lambda (exn)
-                          (simple-format
-                           (current-error-port)
-                           "error: when deleting substitute cache file: ~A\n"
-                           exn))
-                      (lambda ()
-                        (delete-file cache-file))
-                      #:unwind? #t))))
+                  ;; Use monitor to avoid multiple threads trying to delete
+                  ;; the same file at the same time
+                  (monitor
+                   (when (file-exists? cache-file)
+                     (with-exception-handler
+                         (lambda (exn)
+                           (simple-format
+                            (current-error-port)
+                            "error: when deleting substitute cache file: ~A\n"
+                            exn))
+                       (lambda ()
+                         (delete-file cache-file))
+                       #:unwind? #t)))))
               (or directories '())))
 
   (let ((narinfos