We were hit randomly a couple of days ago by a random behaviour : Two docker images we had built ~3 months ago and were residing in github packages in each corresponding repository could no longer be pulled.
The error we were seeing (both within our K8S cluster and locally) was
$ docker pull docker.pkg.github.com/myorg/myrepo/myimage:v0.0.1-dev.22 WARNING: ⚠️ Failed to pull manifest by the resolved digest. This registry does not appear to conform to the distribution registry specification; falling back to pull by tag. This fallback is DEPRECATED, and will be removed in a future release. Please contact admins of https://docker.pkg.github.com. ⚠️ v0.0.1-dev.22: Pulling from myorg/myrepo/myimage e7c96db7181b: Already exists 264026bbe255: Pulling fs layer a71634c55d29: Pulling fs layer 5595887beb81: Downloading 2ce452eda13f: Waiting 7e1411315519: Waiting 8327ab7588c9: Waiting cb0530faab3a: Waiting 68d568ddd158: Waiting 7be10ee9ca48: Waiting unknown blob
The solution was to re-build the images however, we would like to understand what could cause this behaviour. As mentioned above, no changes occurred from our side regarding these docker images.