imagetools create should propagate the original error #1726
Description
If I'm unauthenticated and try to use imagetools create, it fails without showing me the original error that would help to find out the issue:
$ docker buildx imagetools create --tag foo.com/user/repo:latest --tag foo.com/user/repo:v1.0 foo.com/user/repo:v1.0.0
#1 [internal] pushing foo.com/user/repo:v1.0
#1 0.000 pushing sha256:1bf960763a14552b30e1e91967966b659f595ea854cf2c2c445f1c529853bcc4 to foo.com/user/repo:v1.0
#1 ...
#2 [internal] pushing foo.com/user/repo:latest
#0 0.000 pushing sha256:1bf960763a14552b30e1e91967966b659f595ea854cf2c2c445f1c529853bcc4 to foo.com/user/repo:latest
#2 ERROR: failed to copy after 5 retries
#1 [internal] pushing foo.com/user/repo:v1.0
#1 ERROR: failed to copy after 5 retries
------
> [internal] pushing foo.com/user/repo:v1.0:
#1 0.000 pushing sha256:1bf960763a14552b30e1e91967966b659f595ea854cf2c2c445f1c529853bcc4 to foo.com/user/repo:v1.0
------
------
> [internal] pushing foo.com/user/repo:latest:
#0 0.000 pushing sha256:1bf960763a14552b30e1e91967966b659f595ea854cf2c2c445f1c529853bcc4 to foo.com/user/repo:latest
------
ERROR: failed to copy after 5 retries
ERROR: failed to copy after 5 retries
ERROR: failed to copy after 5 retries
It does not seem to be in buildx but containerd: https://github.com/containerd/containerd/blob/5885db62c856e703f11f2195c54efbec5d00a788/content/helpers.go#L206
Bisecting indicates containerd/containerd#6995 is the PR introducing this issue that has been fixed by @jedevc in containerd/containerd#7985 for pushWriter but we also need to propagate the original error for the Copy helper: https://github.com/containerd/containerd/blob/5885db62c856e703f11f2195c54efbec5d00a788/content/helpers.go#L143-L207
@akhilerm Let me know if you want another issue on containerd repo.