S3 has 100% of misses all of the time

[kornelski]

How can I diagnose issues with sccache apparently not working with S3?

export SCCACHE_BUCKET=…
export AWS_ACCESS_KEY_ID=…
export AWS_SECRET_ACCESS_KEY=…
export RUSTC_WRAPPER=$(which sccache)
cargo clean
cargo build --release
cargo clean
cargo build --release

If I do the above without setting up S3, I get cache hits on local disk.

However, with S3 enabled I only get cache misses. The S3 bucket remains completely empty.

How can I diagnose what went wrong?

Compile requests 233
Compile requests executed 205
Cache hits 0
Cache misses 205
Cache timeouts 0
Cache read errors 0
Forced recaches 0
Cache write errors 181
Compilation failures 0
Cache errors 0
Non-cacheable compilations 0
Non-cacheable calls 28
Non-compilation calls 0
Unsupported compiler calls 0
Average cache write 0.000 s
Average cache read miss 6.322 s
Average cache read hit 0.000 s
Cache location S3, bucket: Bucket(name=…, base_url=http://….s3.amazonaws.com/)

[kornelski]

RUST_LOG=sccache=trace sccache rustc …
cat sccache.log

[luser]

Did you get this sorted out? We have an existing issue on file about this: #45

Right now it's hard to diagnose if your S3 configuration isn't correct.

[kornelski]

Yes, I've eventually found the log, and that PUT requests were failing. It turned out to be permissions problem (I can't believe I had to write custom JSON in AWS to set up such a basic thing as protected s3 bucket).

It'd be great if you could add proper diagnostic for it, e.g. try making a PUT request at server startup and fail loudly if that request is rejected.

[turbo]

I seond @kornelski 's suggestion.