Error 400 while using sccache

[alekitto]

Hi and thanks for your work on this.

I'm currently encountering an error while trying to use this cache server with sccache.
When enabling gha, sccache fails with the following error:

sccache: error: Server startup failed: cache storage failed to read: Unexpected (permanent) at read => {
  "error": true,
  "url": "https://<redacted>/twirp/github.actions.results.api.v1.CacheService/GetCacheEntryDownloadURL",
  "statusCode": 400,
  "statusMessage": "Invalid body: [\n  {\n    \"expected\": \"object\",\n    \"code\": \"invalid_type\",\n    \"path\": [],\n    \"message\": \"Invalid input: expected object, received string\"\n  }\n]",
  "message": "Invalid body: [\n  {\n    \"expected\": \"object\",\n    \"code\": \"invalid_type\",\n    \"path\": [],\n    \"message\": \"Invalid input: expected object, received string\"\n  }\n]"
}

While the hosted cache server works as expected

[LouisHaftmann]

Looks like sccache uses protobuf instead of json: https://opendal.apache.org/docs/rust/src/opendal/services/ghac/core.rs.html#152

Will fix!

[aki-luxor]

Getting similar issue.