refactor!: remove 'cache-dotcache' key

Author: ahal

docs/reference/migrations.rst

@@ -3,6 +3,23 @@ Migration Guide
 
 This page can help when migrating Taskgraph across major versions.
 
+12.x -> 13.x
+------------
+
+* Remove all ``run.cache-dotcache`` keys. If it was set to ``true``, replace it
+  with:
+
+  .. code-block:: yaml
+
+     run:
+       use-caches: [checkout, <caches>]
+
+  Where caches can be any of ``cargo``, ``pip``, ``uv`` or ``npm``. If the task
+  was setting up ``.cache`` for another tool, a mount will need to be created
+  for it manually. If ``use-caches`` was previously set to ``false``, omit
+  ``checkout`` in the example above. If ``use-caches`` was previously set to
+  ``true``, replace ``true`` with the value above (including ``checkout``).
+
 11.x -> 12.x
 ------------
 
@@ -110,7 +127,7 @@ This page can help when migrating Taskgraph across major versions.
 5.x -> 6.x
 ----------
 
-* Replace all uses of ``command-context` with the more generalized ``task-context``
+* Replace all uses of ``command-context`` with the more generalized ``task-context``
 
 4.x -> 5.x
 ----------

src/taskgraph/transforms/run/run_task.py

@@ -28,10 +28,6 @@
 run_task_schema = Schema(
     {
         Required("using"): "run-task",
-        # if true, add a cache at ~worker/.cache, which is where things like pip
-        # tend to hide their caches.  This cache is never added for level-1 tasks.
-        # TODO Once bug 1526028 is fixed, this and 'use-caches' should be merged.
-        Required("cache-dotcache"): bool,
         # Which caches to use. May take a boolean in which case either all
         # (True) or no (False) caches will be used. Alternatively, it can
         # accept a list of caches to enable. Defaults to only the checkout cache
@@ -115,7 +111,6 @@ def common_setup(config, task, taskdesc, command):
 
 
 worker_defaults = {
-    "cache-dotcache": False,
     "checkout": True,
     "sparse-profile": None,
     "run-as-root": False,
@@ -142,16 +137,6 @@ def docker_worker_run_task(config, task, taskdesc):
     command = run.pop("run-task-command", ["/usr/local/bin/run-task"])
     common_setup(config, task, taskdesc, command)
 
-    if run.get("cache-dotcache"):
-        worker["caches"].append(
-            {
-                "type": "persistent",
-                "name": "{project}-dotcache".format(**config.params),
-                "mount-point": "{workdir}/.cache".format(**run),
-                "skip-untrusted": True,
-            }
-        )
-
     run_command = run["command"]
 
     # dict is for the case of `{'task-reference': str}`.
@@ -184,13 +169,6 @@ def generic_worker_run_task(config, task, taskdesc):
     common_setup(config, task, taskdesc, command)
 
     worker.setdefault("mounts", [])
-    if run.get("cache-dotcache"):
-        worker["mounts"].append(
-            {
-                "cache-name": "{project}-dotcache".format(**config.params),
-                "directory": "{workdir}/.cache".format(**run),
-            }
-        )
     worker["mounts"].append(
         {
             "content": {

taskcluster/docker/python/Dockerfile

@@ -6,7 +6,7 @@ FROM debian:bookworm-slim
 LABEL maintainer="Release Engineering <release@mozilla.com>"
 
 VOLUME /builds/worker/checkouts
-VOLUME /builds/worker/.cache
+VOLUME /builds/worker/.task-cache/uv
 
 # Add worker user
 RUN mkdir -p /builds && \

taskcluster/kinds/check/kind.yml

@@ -29,7 +29,7 @@ task-defaults:
     run:
         using: run-task
         cwd: '{checkout}'
-        cache-dotcache: true
+        use-caches: [checkout, uv]
 
 tasks:
     type:

taskcluster/kinds/codecov/kind.yml

@@ -44,6 +44,7 @@ tasks:
         run:
             using: run-task
             cwd: '{checkout}'
+            use-caches: [checkout, uv]
             command: >-
                 uv run coverage combine --data-file $MOZ_FETCHES_DIR/coverage $MOZ_FETCHES_DIR &&
                 uv run coverage xml --data-file $MOZ_FETCHES_DIR/coverage -o $MOZ_FETCHES_DIR/coverage.xml &&

taskcluster/kinds/doc/kind.yml

@@ -21,7 +21,7 @@ task-defaults:
     run:
         using: run-task
         cwd: '{checkout}'
-        cache-dotcache: true
+        use-caches: [checkout, uv]
 
 tasks:
     generate:

taskcluster/kinds/test/kind.yml

@@ -34,7 +34,7 @@ task-defaults:
     run:
         using: run-task
         cwd: '{checkout}'
-        cache-dotcache: true
+        use-caches: [checkout, uv]
 
 tasks:
     unit: