ERROR: invalid tag " [ tag] : latest": Invalid reference format

[Timmysworld]

Hey,
this is my first time messing with docker and the Github actions. I am following this link here https://docs.docker.com/build/ci/github-actions/ step by step. but whenever I try to run to see if it gets push to the docker hub i get this error:

build
buildx failed with: ERROR: invalid tag "***/.DotNetCICD:latest": invalid reference format

not sure where to start to debug or why its doing that. Chat gpt share one thing but im not sure if i trust it being i am following a tutorial from the docker site.

[thaJeztah]

.DotNetCICD looks like it starts with a dot (.) which is not allowed in repository (image) names; likely should also be all lowercase

[thaJeztah]

Also see;

• https://docs.docker.com/engine/reference/commandline/tag/
• and (the technical implementation of image references) https://pkg.go.dev/github.com/distribution/reference

[Timmysworld]

Thank you that fixed my problem

[thaJeztah]

You're welcome!

[Aamir017]

buildx failed with: ERROR: invalid tag "/subzero:latest": invalid reference format
facing the same issue

[thaJeztah]

@Aamir017 looks like that reference is missing something at the start; it cannot start with a / - is the registry prefix or username missing? (e.g. yourname/subzero:latest if it's on Docker Hub, or some-registry.com/yourname/subzero:latest)?

[QingminChen]

You save my life! It fixed my careless issue, thank you!