dotnet
Unable to pull image from mcr.microsoft.com
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Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1108670 Build error leg or test failing:
Error Message
Fill the error message using step by step known issues guidance.
{
"ErrorMessage": "Unable to pull image mcr.microsoft.com/dotnet-buildtools/prereqs",
"BuildRetry": true,
"ExcludeConsoleLog": false
}
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Build: :mag_right: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1108670 Result validation: :warning: Validation could not be done without an Azure DevOps build URL on the issue. Please add it to the "Build: :mag_right:" line. Validation performed at: 8/1/2025 8:10:46 AM UTC
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Summary
| 24-Hour Hit Count | 7-Day Hit Count | 1-Month Count |
|---|---|---|
| 8 | 62 | 229 |
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This is from a preview6 run from Jun 20th, it might've been fixed in main already.
We are hitting a similar one: Unable to pull image mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-sqlserver-amd64 in efcore
https://dev.azure.com/dnceng-public/public/_build/results?buildId=1106421&view=logs&j=f95328f7-07f5-5106-5c2a-5dc7069f305c&t=e2f3026d-346a-509b-3549-57236476a9cb
https://dev.azure.com/dnceng-public/public/_build/results?buildId=1108065&view=logs&j=f95328f7-07f5-5106-5c2a-5dc7069f305c&t=e2f3026d-346a-509b-3549-57236476a9cb
If you look at the run_client.py log for the workitem you see this:
2025-07-30T19:06:18.967Z INFO executor(114) run Successfully downloaded work item payload
2025-07-30T19:06:18.967Z INFO interval(67) set_abort_after_timer Set the timer's abort_after to 5460 seconds from now: abort_after = 2025-07-30 20:37:18.967591
2025-07-30T19:06:19.045Z INFO dockerhelper(70) ensure_docker_running Ensuring docker is running: Current status=0
2025-07-30T19:06:19.045Z INFO dockerhelper(76) ensure_docker_running Done.
2025-07-30T19:06:19.046Z INFO dockerhelper(22) cleanup Cleaning up Docker on the machine
2025-07-30T19:06:19.049Z INFO dockerhelper(39) pull Pulling image dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly from registry mcr.microsoft.com...
2025-07-30T19:06:20.457Z WARNING dockerhelper(47) pull Hit exception trying to pull: 404 Client Error: Not Found ("no such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly: No such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly") Retrying up to 5 times
2025-07-30T19:06:30.663Z WARNING dockerhelper(47) pull Hit exception trying to pull: 404 Client Error: Not Found ("no such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly: No such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly") Retrying up to 5 times
2025-07-30T19:06:40.876Z WARNING dockerhelper(47) pull Hit exception trying to pull: 404 Client Error: Not Found ("no such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly: No such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly") Retrying up to 5 times
2025-07-30T19:06:51.129Z WARNING dockerhelper(47) pull Hit exception trying to pull: 404 Client Error: Not Found ("no such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly: No such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly") Retrying up to 5 times
2025-07-30T19:07:02.076Z WARNING dockerhelper(47) pull Hit exception trying to pull: 404 Client Error: Not Found ("no such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly: No such image: mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-webassembly") Retrying up to 5 times
2025-07-30T19:07:12.086Z ERROR dockerhelper(54) pull Pull unsuccessful after 5 tries!
2025-07-30T19:07:12.087Z INFO interval(70) cancel_abort_after Cancel abort_after for timer
2025-07-30T19:07:12.087Z INFO executor(729) _execute_command_in_container The return code was not 0. Sleeping for 30 seconds in case it's still writing to disk.
So for some reason it's getting 404 but this doesn't make much sense.
I see the same thing for the mcr.microsoft.com/dotnet-buildtools/prereqs:ubuntu-22.04-helix-sqlserver-amd64 image that @AndriySvyryd mentioned.
@mthalman do you have any idea what would cause these docker pull errors? The images seem to still be present in https://github.com/dotnet/dotnet-buildtools-prereqs-docker. I would expect the tags to always exist.
Since the tag is correct and the image does exist, it would seem this is a service-level issue. You can write up an issue at https://github.com/microsoft/containerregistry.
This hits many different images. For example, I just saw Unable to pull image mcr.microsoft.com/dotnet-buildtools/prereqs:debian-13-helix-amd64. I have generalized the error message to include all prereq image. Also, I have set retry to true.
