**Problem**
`remoteCacheHeaders` entries are parsed in GrpcActionCacheStore.AuthCallCredentials
with h.split("="), which splits on every =. Java's split discards trailing empty
strings, so a Basic auth header such as authorization=Basic dXNlcjpwdw== produces
exactly two elements and matches List(k, v) with the base64 padding silently removed.
The truncated credential is rejected by the cache server with UNAUTHENTICATED.
**Solution**
Split on the first = only, keeping the remainder of the string verbatim as the header
value. The error case narrows to a header containing no = at all.
Generated-by: Claude Opus 5
The byteStreamStub lazy val applied withDeadlineAfter once, baking in an
absolute deadline that was reused for the store's whole (session-long)
lifetime. remoteTimeoutInSec after the first blob transfer, every later
ByteStream read/write was rejected with DEADLINE_EXCEEDED, so the remote
cache could neither upload nor download blobs >chunkSizeBytes for the rest
of the sbt server's life.
Derive a fresh stub with the deadline per RPC so each call gets its own
relative timeout.
Co-authored-by: Yannick Heiber <[email protected]>
Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>
**Problem**
Chunked upload/download doesn't work.
**Solution**
1. This fixes the SERVICE_NAME shading.
2. This fixes the resource name.
3. This fixes download stream processing.
**Problem**
BatchUpdateBlobsRequest suffers from gRPC's message size limitation.
**Solution**
For larger files, we switch to using the ByteStream API, chunked to 1MB at a time.
KilianSwissborg
Eugene Yokota
xuwei-k
Adrien Piquerez