Gradle "Could not download" Artifact - Fix Flaky Fetches in CI

By Daniel Zoghalchali·Latchkey

Gradle found the artifact in a repository but could not download its bytes - a read timeout or connection drop during the transfer. This is typically a transient network blip that clears on retry.

What this error means

Resolution fails with Could not download <group:name:version> and an underlying Read timed out or Connection reset. Re-running the job often succeeds with no change.

gradle output

> Could not download lib-2.3.1.jar (com.example:lib:2.3.1)
   > Could not get resource 'https://repo.maven.apache.org/.../lib-2.3.1.jar'.
      > Read timed out

Common causes

Transient timeout or reset mid-download

A slow mirror or a brief network drop times out the transfer. The artifact exists; only the download failed.

No local cache, so every jar is fetched live

Without a warm ~/.gradle/caches, CI downloads everything on each run, multiplying the chance one fetch fails.

How to fix it

Raise Gradle’s network timeouts and retry

Give downloads a longer timeout so slow mirrors do not abort, and let CI retry the step.

Terminal

./gradlew build \
  -Dorg.gradle.internal.http.connectionTimeout=60000 \
  -Dorg.gradle.internal.http.socketTimeout=60000

Cache the Gradle caches in CI

A warm cache means most artifacts are already present, so a live download failure is rare.

.github/workflows/ci.yml

- uses: actions/cache@v4
  with:
    path: |
      ~/.gradle/caches
      ~/.gradle/wrapper
    key: gradle-${{ hashFiles('**/*.gradle*', 'gradle/wrapper/gradle-wrapper.properties') }}

How to prevent it

Cache ~/.gradle/caches and ~/.gradle/wrapper in CI.
Raise connection/socket timeouts for slow mirrors.
Resolve through a pull-through mirror to reduce live downloads.

Frequently asked questions

What causes ""Could not download""?