Changes to artifact hosting: direct S3 redirects

In order to improve the performance of our artifacts hosting, we are trialling an upcoming change to 302 redirect non-HTML artifact downloads directly to a short-lived pre-signed S3 URL.

Over the coming days we will be doing a staged percentage-based rollout of this feature, and listening for your feedback. We hope you will be pleased with the results.

If using a web browser (to view HTML resources such as test / coverage reports or download tarballs / zip files) you will not need to change your behaviour, as browsers follow redirects by default.

However, if you are using curl or another HTTP client that does not follow redirects by default, you will need to enable redirect support (wget follows redirects by default, while curl requires the -L switch).

An example with curl might be:

$ curl -H'Circle-Token: XXXXXX' '' 
Redirecting to <>


$ curl -L -H'Circle-Token: XXXXXX' ''
some logs......
some logs......
some logs......

I don’t have any feedback on download speed, but this is not a very responsible way to roll out a known breaking change.

There was essentially zero notice, and the only announcement is in a forum that your customers are very unlikely to be proactively checking. The only reason I found this at all is because I came in this morning to broken nightly builds.

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Hi Phil. Sorry to hear that this affected your builds. Thanks for letting us know this has caused an issue for you.

We have temporarily paused the rollout, and will be reaching out to organisations that use tools that do not follow redirects by default.

Again, we appreciate you letting us know.

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