Artifact and cache failures — No files were found with the provided path

Log signatures

No files were found with the provided path
an artifact with this name already exists
Failed to CreateArtifact
Cache service responded with 503
reserveCache failed

What’s happening

The artifact/cache storage layer failed, for one of four reasons: a wrong path ("No files were found with the provided path" — the build put output somewhere else, or the build silently produced nothing), a name collision ("an artifact with this name already exists" — classic in matrix jobs all uploading "build"), a stale action version (v3→v4 of the artifact actions changed naming semantics and broke many pipelines), or a transient storage outage ("Cache service responded with 503"). Crucially, cache restore failures are non-fatal by design — a failed restore should slow the build down, never break it. If a failed restore breaks your build, the build has a hidden dependency on cache contents, and that's the real bug.

Fix playbook

1. 1Identify which of the four causes you have from the signature.
2. 2Wrong path: add ls -laR <path> just before the upload step. Nine times out of ten the build output simply isn't where the workflow thinks it is.
3. 3Name collision in a matrix: suffix the artifact name with matrix variables — name: build-${{ matrix.os }}-${{ matrix.version }}.
4. 4Storage 5xx: retry. It's their outage, not your bug.
5. 5Bump pinned actions/upload-artifact / actions/download-artifact / actions/cache versions if they're more than a major behind. Do not change application code for this class.