jwmossmoz/task-discovery

Task Discovery

Query the Taskcluster task graph to find tasks by worker type. Useful for worker pool migrations (e.g., win11-64-24h2 → win11-64-25h2) and crafting precise mach try pushes.

Usage

uv run ~/.claude/skills/task-discovery/scripts/discover.py [options]

Output Formats

| Format | Description | |--------|-------------| | labels | One task label per line, sorted (default) | | json | {"worker_type": "...", "count": N, "by_kind": {...}, "labels": [...]} | | summary | Grouped by kind with counts per worker type (human-readable) | | query | -q '<label>' flags for mach try fuzzy |

Examples

# List all unique worker types in the task graph
uv run discover.py --list-worker-types

# Find all tasks running on win11-64-24h2 (substring match)
uv run discover.py -w win11-64-24h2 -o summary

# Exact match only — excludes -gpu, -hw, -source variants
uv run discover.py -w win11-64-24h2 --exact -o json

# Filter to browsertime tasks on hardware workers
uv run discover.py -w win11-64-24h2-hw -k browsertime -o labels

# Generate mach try flags for a migration
uv run discover.py -w win11-64-24h2 -k test -o query | head -20

# Regex match for multiple variants
uv run discover.py -w 'win11-64-24h2(-gpu|-source)' --regex -o summary

# Check autoland instead of mozilla-central
uv run discover.py -w win11-64-24h2 --branch autoland -o summary

Migration Workflow

When migrating tasks from one pool to another:

1. Audit current pool: discover.py -w win11-64-24h2 -o summary
2. Get task list: discover.py -w win11-64-24h2 -k test -o labels > tasks.txt
3. Build try command: Use query output piped into mach try fuzzy

mach try fuzzy $(uv run discover.py -w win11-64-24h2-hw -k browsertime -o query)

Options Reference

| Flag | Default | Description | |------|---------|-------------| | -w, --worker-type | — | Worker type pattern | | --exact | off | Require exact match (no substring) | | --regex | off | Treat pattern as regex | | -o, --output | labels | Output format | | --branch | mozilla-central | Branch to fetch from | | -k, --kind | all | Filter to specific kind(s), repeatable | | --timeout | 120 | HTTP timeout in seconds | | --list-worker-types | — | List all unique worker types (no -w needed) |

Gotchas

• Default branch is mozilla-central. For migration planning, pass --branch autoland — autoland is the integration branch upstream of central and reflects newer task graphs first.
• -w is substring match by default. win11-64-24h2 will pull in -gpu, -hw, and -source variants. Use --exact or --regex when you don't want them.
• The decision task graph can be 30+ MB; the 120s timeout default is fine on home internet but can stall on bad links — bump with --timeout.
• query output is designed for mach try fuzzy $(...) — paste it through xargs/$() rather than copying labels by hand.