Build dev from test-pypi, use RCs

.github/workflows/v2-build-branch-dev.yml

@@ -2,7 +2,8 @@ name: V2 Build QML Branch - Dev
 on:
   workflow_dispatch:
   schedule:
-    - cron: '0 0 * * 1,3,5' # At 00:00 on Sunday (Monday am), Tuesday (Wednesday am), Thursday (Friday am).
+    - cron: '0 5 * * 1,3,5' # At 05:00 (12am EST) on Sunday (Monday am), Tuesday (Wednesday am), Thursday (Friday am).
+    #- cron: '0 10 * * *' # At 10:00 (5am EST) on every day-of-week. Use this during feature freeze.
 
 concurrency:
   group: v2-build-qml-demo-branch-dev

.github/workflows/v2-build-branch-master.yml

@@ -2,7 +2,7 @@ name: V2 Build QML Branch - Master
 on:
   workflow_dispatch:
   schedule:
-    - cron: '0 0 * * 1,3,5' # At 00:00 on Sunday (Monday am), Tuesday (Wednesday am), Thursday (Friday am).
+    - cron: '0 5 * * 1,3,5' # At 05:00 (12am EST) on Sunday (Monday am), Tuesday (Wednesday am), Thursday (Friday am).
 
 concurrency:
   group: v2-build-qml-demo-branch-master

.github/workflows/v2-build-demos.yml

@@ -169,6 +169,7 @@ jobs:
 
       - name: Install pandoc, opencl, and graphviz
         run: |
+          sudo apt-get update
           sudo apt-get install -y \
             ocl-icd-opencl-dev \
             pandoc \

dependencies/constraints-plc-dev.txt

@@ -0,0 +1,8 @@
+# Specifies constraints for PennyLane, Lightning, and Catalyst dev builds.
+# These need to be installed separately, and in a specific order, and as such are not controlled 
+# by the constraints-dev.txt file. Please do not change the order of these constraints.
+# Use upper bounds targeting the next-to-next stable release so we continue to build RC branches during feature freeze.
+
+pennylane-catalyst<0.15.0
+pennylane-lightning<0.45.0
+pennylane<0.45.0

lib/qml/context.py

@@ -49,6 +49,10 @@ def stable_constraints_file(self) -> Path:
     def dev_constraints_file(self) -> Path:
         return self.repo_root / "dependencies" / "constraints-dev.txt"
 
+    @property
+    def plc_dev_constraints_file(self) -> Path:
+        return self.repo_root / "dependencies" / "constraints-plc-dev.txt"
+
     @property
     def build_requirements_file(self) -> Path:
         return self.repo_root / "dependencies" / "requirements-build.txt"

lib/qml/lib/demo.py

@@ -292,30 +292,24 @@ def _build_demo(
         # If dev, we need to re-install the latest Catalyst, then Lightning, then PennyLane
         # in that order, regardless of conflicts/warnings. 
         if dev:
-            # Catalyst
-            cmds.pip_install(
-                build_venv.python,
-                "--upgrade",
-                "--extra-index-url",
-                "https://test.pypi.org/simple/",
-                "PennyLane-Catalyst",
-                use_uv=False,
-                quiet=False,
-                pre=True,
-            )
-            # Lightning
-            cmds.pip_install(
-                build_venv.python,
-                "--upgrade",
-                "--extra-index-url",
-                "https://test.pypi.org/simple/",
-                "PennyLane-Lightning",
-                use_uv=False,
-                quiet=False,
-                pre=True,
-            )
-    if dev:
-        # Need dev version of PennyLane to build, whether or not we're executing
+            with open(ctx.plc_dev_constraints_file, "r") as f:
+                packages = f.readlines()
+                for package in packages:
+                    package = package.strip()
+                    if package and not package.startswith("#"):
+                        cmds.pip_install(
+                            build_venv.python,
+                            "--upgrade",
+                            "--index-url",
+                            "https://test.pypi.org/simple/",
+                            package,
+                            use_uv=False,
+                            quiet=False,
+                            pre=True,
+                        )
+
+    elif dev:
+        # Need latest version of PennyLane to build, whether or not we're executing
         cmds.pip_install(
             build_venv.python,
             "--upgrade",