Unsure about the necessity of SCCACHE_S3_KEY_PREFIX when using sccache across multiple projects

[jselig-rigetti]

Hello, from https://github.com/mozilla/sccache/blob/main/docs/S3.md#s3

You can also define a prefix that will be prepended to the keys of all cache objects created and read within the S3 bucket, effectively creating a scope. To do that use the SCCACHE_S3_KEY_PREFIX environment variable. This can be useful when sharing a bucket with another application.

Does the word application here mean some non-sccache related use of the bucket, or does it mean separate rust projects? I've noticed some ephemeral build errors in dependencies when multiple projects are using the same bucket so I figured (without the time or skill to do a more thorough investigation) that it would be a reasonable hedge against a potential class of errors if each project used a different SCCACHE_S3_KEY_PREFIX.

Opening this as an issue so that hopefully any clarification makes it back into the documentation.

[Xuanwo]

Hi, sccache ensures that the same bucket can be used by multiple instances simultaneously. Different applications refer to other programs that might use the bucket at the same time—for example, the bucket could also be used to store CI logs.