CUDA single lock

Circumvent issues with https://github.com/prefix-dev/pixi/issues/1051 and declare a single manifest that also contains CUDA environment support.

pyproject.toml

@@ -28,11 +28,6 @@ classifiers = [
   "Topic :: Software Development :: Libraries :: Python Modules",
 ]
 
-# warning: if you add/remove/pin dependencies, also update
-# tool.pixi.dependencies in this file, and the equivalent settings at and
-# helpers/cuda/pixi.toml files
-#
-# (c.f.: https://github.com/prefix-dev/pixi/issues/1051)
 dependencies = [
   "clapper",
   "click",
@@ -83,10 +78,6 @@ platforms = ["linux-64", "osx-arm64"]
 [tool.pixi.system-requirements]
 linux = "4.19.0"
 
-# warning: if you add/remove/pin dependencies, also update project.dependencies
-# in this file, and the equivalent settings at and helpers/cuda/pixi.toml files
-#
-# (c.f.: https://github.com/prefix-dev/pixi/issues/1051)
 [tool.pixi.dependencies]
 clapper = "*"
 click = "*"
@@ -169,11 +160,23 @@ uv = "*"
 [tool.pixi.feature.dev.tasks]
 uv-update-lock = "uv pip compile -q pyproject.toml --python-platform=linux -o uv.lock"
 
+[tool.pixi.feature.cuda]
+channels = ["nvidia", {channel = "pytorch", priority = -1}]
+platforms = ["linux-64", "osx-arm64"]
+
+[tool.pixi.feature.cuda.system-requirements]
+cuda = "12.1"
+
+[tool.pixi.feature.cuda.target.linux-64.dependencies]
+cuda = { version = "*", channel = "nvidia" }
+pytorch-cuda = { version = "12.1.*", channel = "pytorch" }
+
 [tool.pixi.environments]
 default = { features = ["qa", "build", "doc", "test", "dev", "py312", "self"] }
 qa-ci = { features = ["qa", "py312"] }
 build-ci = { features = ["build", "py312"] }
 test-ci-311 = { features = ["test", "dev", "py311", "self"] }
+cuda = { features = ["qa", "build", "doc", "test", "dev", "py312", "cuda", "self"] }
 
 [tool.hatch.version]
 source = "versioningit"