Grunt watch spawn:false leads to persistent global state

Problem Context

The goal is to understand how the watch task’s spawn option influences global state across successive file changes. In particular, when spawn:false is used, tasks run in the same process, allowing variables and configuration to persist. This can be advantageous for speed but may introduce stale or corrupted data, memory leaks, and unpredictable plugin behavior.

Constraints and Uncertainty

• Global variables or mutable configuration objects modified by plugins (e.g., grunt-contrib-uglify) may retain changes between runs.
• The default behaviour (spawn:true) creates a new child process for each change, ensuring isolation but adding overhead.
• Behavior differences have been observed between Grunt 0.4.x and 1.x releases, making reproducibility version‑dependent.
• It is unclear when the trade‑off favors speed over reliability for a given project.

Diagnostic Questions

1. What observable indicators in the logs or runtime confirm that a global state change has persisted across watch executions?
2. Under what project conditions (size, plugin set, memory constraints) does spawn:false lead to measurable memory growth or task failures?
3. Which diagnostic steps can reliably distinguish between issues caused by stale global data and those caused by process isolation?