Pushing images to dockerhub stopped working

[gebi]

Actual behavior

Kaniko exits with exit code 1 with the following message and and does not build the image:

error checking push permissions -- make sure you entered the correct tag name,
and that you are authenticated correctly, and try again: checking push permission for
"foo/bar:bionic-99": UNAUTHORIZED: authentication required; [map[Action:pull Class:
Name:mgit/clamav Type:repository] map[Action:push Class: Name:foo/bar Type:repository]]

This worked with the same build pipeline and no changes 3 months ago with the following image:

Using Docker executor with image gcr.io/kaniko-project/executor:debug ...
Pulling docker image gcr.io/kaniko-project/executor:debug ...
Using docker image sha256:2aa254b4837c242c7de87956438eaba70f97a2768ab0870819fd20e09df15cf6 for gcr.io/kaniko-project/executor:debug ...

Expected behavior

Kaniko to upload image to dockerhub like the version 3 months ago was able to. There where no changes, and it works if i go back to an older kaniko version.

To Reproduce Steps to reproduce the behavior:

1. ... with the following pseudo .gitlab-ci.yml

image:
  name: gcr.io/kaniko-project/executor:debug
  entrypoint: [""]

stages:
  - foo

build-foo:
  stage: foo
  script:
    - echo "{\"auths\":{\"index.docker.io\":{\"auth\":\"${CI_DOCKERHUB_AUTH}\"}}}" > /kaniko/.docker/config.json
    - >
      /kaniko/executor --context "${CI_PROJECT_DIR}/foo" --dockerfile "${CI_PROJECT_DIR}/foo/Dockerfile"
      --destination foo/bar:blub-${CI_PIPELINE_IID}"
      --destination foo/bar:blub"

2. ... build it

Additional Information

• Dockerfile Please provide either the Dockerfile you're trying to build or one that can reproduce this error.
• Build Context Please provide or clearly describe any files needed to build the Dockerfile (ADD/COPY commands)

• Kaniko Image (fully qualified with digest)

  Using Docker executor with image gcr.io/kaniko-project/executor:debug ...
  Pulling docker image gcr.io/kaniko-project/executor:debug ...
  Using docker image sha256:2ec307dcf7f52dcf700ea0fbc65d448f46365cfac69567e8177bf12b80942f54 for gcr.io/kaniko-project/executor:debug ...

  Triage Notes for the Maintainers

  Description	Yes/No
  Please check if this a new feature you are proposing	- [ ]
  Please check if the build works in docker but not in kaniko	- [x]
  Please check if this error is seen when you use --cache flag	- [ ]
  Please check if your dockerfile is a multistage dockerfile	- [ ]