Build Cache for Gradle v2.20.6

Changelog
1

What’s Changed

  • Bump bitrise-build-cache-cli to v2.7.3 — moves the ccache IPC socket default from <Getwd()>/ccache-ipc.sock to <TempDir()>/ccache-ipc.sock so the AF_UNIX socket lives outside the project workdir. Fixes EAS-CLI Cannot copy a socket file: cp returned EINVAL failures during EAS’s shallow-clone copy step. No Gradle-side behavior change in this release.