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Error: not a valid repository/tag: invalid reference format

I’m currently using Docker installed in Google Cloud. I’ve been able to successfully run the example walkthrough to run helloapp (For reference: Quickstart for Docker  |  Artifact Registry documentation  |  Google Cloud ) . However, when I attempt to use another Google Cloud marketplace image, specifically CentOS, I receive the following command line error (using gcloud CLI to tag):

Error parsing reference: "" is not a valid repository/tag: invalid reference format

The command I’m entering is: docker tag \

The only difference from the example walkthrough and the command which generates an error is in the marketplace locations. For reference, here is the command that runs successfully:

docker tag \

Any help greatly appreciated!!

For reference (docker version):

Client: Docker Engine - Community
Version: 20.10.3
API version: 1.41
Go version: go1.13.15
Git commit: 48d30b5
Built: Fri Jan 29 14:33:25 2021
OS/Arch: linux/amd64
Context: default
Experimental: true
Server: Docker Engine - Community
Version: 20.10.3
API version: 1.41 (minimum version 1.12)
Go version: go1.13.15

For those interested. The error ended up being a single “spacebar” after the \ . Changing from:


Fixed the issue