While different tools have different specific commands, the process of "debugging the action cache" generally follows these steps: 1. Inspecting Input Digests
If you're compiling binaries, ensure you strip timestamps from the output, as these will change the file hash even if the code is identical. The Cost of Ignoring Cache Issues debug-action-cache
Some systems are sensitive to the order in which files are listed. Ensure your glob patterns or file lists are sorted. While different tools have different specific commands, the
Maximizing Build Efficiency: A Deep Dive into debug-action-cache Ensure your glob patterns or file lists are sorted
In systems like Bazel, you can use flags like --execution_log_json_file . This allows you to see the exact metadata sent to the cache. You can compare logs from two different builds to see which file or environment variable caused the discrepancy. 2. Identifying "Dirty" Environment Variables
A common culprit for cache misses is the environment. If your build script pulls in a timestamp, a random seed, or a local file path (e.g., /Users/john/project vs /Users/jane/project ), the cache will treat them as different actions. 3. Verbose Logging