Fix UV_PYTHON default value to prevent empty parameter error

The UV_PYTHON setting had an empty default in metadata, causing
uv venv to fail with "a value is required for '--python <PYTHON>'".

Fixed by setting UV_PYTHON default to $(PRIMARY_PYTHON) in mxenv.mk
metadata and updating test expectations.

Author: jensens

Makefile

@@ -68,8 +68,8 @@ PYTHON_PACKAGE_INSTALLER?=uv
 # environments with global UV. Passed to `uv venv -p VALUE`. Supports version
 # specs like `3.11`, `3.14`, `cpython@3.14`. Defaults to PRIMARY_PYTHON value
 # for backward compatibility.
-# No default value.
-UV_PYTHON?=
+# Default: $(PRIMARY_PYTHON)
+UV_PYTHON?=$(PRIMARY_PYTHON)
 
 # Flag whether to use virtual environment. If `false`, the
 # interpreter according to `PRIMARY_PYTHON` found in `PATH` is used.
@@ -252,9 +252,6 @@ endif
 USE_GLOBAL_UV:=$(shell [[ "$(PYTHON_PACKAGE_INSTALLER)" == "uv" && "$(UV_AVAILABLE)" == "true" ]] && echo "true" || echo "false")
 USE_LOCAL_UV:=$(shell [[ "$(PYTHON_PACKAGE_INSTALLER)" == "uv" && "$(UV_AVAILABLE)" == "false" ]] && echo "true" || echo "false")
 
-# UV Python version (defaults to PRIMARY_PYTHON for backward compatibility)
-UV_PYTHON?=$(PRIMARY_PYTHON)
-
 # Check if global UV is outdated (non-blocking warning)
 ifeq ("$(USE_GLOBAL_UV)","true")
 UV_OUTDATED:=$(shell uv self update --dry-run 2>&1 | grep -q "Would update" && echo "true" || echo "false")

src/mxmake/tests/expected/Makefile

@@ -59,8 +59,8 @@ PYTHON_PACKAGE_INSTALLER?=pip
 # environments with global UV. Passed to `uv venv -p VALUE`. Supports version
 # specs like `3.11`, `3.14`, `cpython@3.14`. Defaults to PRIMARY_PYTHON value
 # for backward compatibility.
-# No default value.
-UV_PYTHON?=
+# Default: $(PRIMARY_PYTHON)
+UV_PYTHON?=$(PRIMARY_PYTHON)
 
 # Flag whether to use virtual environment. If `false`, the
 # interpreter according to `PRIMARY_PYTHON` found in `PATH` is used.
@@ -158,9 +158,6 @@ endif
 USE_GLOBAL_UV:=$(shell [[ "$(PYTHON_PACKAGE_INSTALLER)" == "uv" && "$(UV_AVAILABLE)" == "true" ]] && echo "true" || echo "false")
 USE_LOCAL_UV:=$(shell [[ "$(PYTHON_PACKAGE_INSTALLER)" == "uv" && "$(UV_AVAILABLE)" == "false" ]] && echo "true" || echo "false")
 
-# UV Python version (defaults to PRIMARY_PYTHON for backward compatibility)
-UV_PYTHON?=$(PRIMARY_PYTHON)
-
 # Check if global UV is outdated (non-blocking warning)
 ifeq ("$(USE_GLOBAL_UV)","true")
 UV_OUTDATED:=$(shell uv self update --dry-run 2>&1 | grep -q "Would update" && echo "true" || echo "false")

src/mxmake/tests/test_parser.py

@@ -21,7 +21,7 @@ def test_MakefileParser(self, tempdir):
             "core.mxenv.PRIMARY_PYTHON": "python3",
             "core.mxenv.PYTHON_MIN_VERSION": "3.7",
             "core.mxenv.PYTHON_PACKAGE_INSTALLER": "pip",
-            "core.mxenv.UV_PYTHON": "",
+            "core.mxenv.UV_PYTHON": "$(PRIMARY_PYTHON)",
             "core.mxenv.VENV_ENABLED": "true",
             "core.mxenv.VENV_CREATE": "true",
             "core.mxenv.VENV_FOLDER": "venv",
@@ -67,7 +67,7 @@ def test_MakefileParser(self, tempdir):
                 "core.mxenv.PRIMARY_PYTHON": "python3",
                 "core.mxenv.PYTHON_MIN_VERSION": "3.7",
                 "core.mxenv.PYTHON_PACKAGE_INSTALLER": "pip",
-                "core.mxenv.UV_PYTHON": "",
+                "core.mxenv.UV_PYTHON": "$(PRIMARY_PYTHON)",
                 "core.mxenv.VENV_ENABLED": "true",
                 "core.mxenv.VENV_CREATE": "true",
                 "core.mxenv.VENV_FOLDER": "venv",

src/mxmake/tests/test_templates.py

@@ -564,7 +564,7 @@ def test_Makefile(self, tempdir):
             "core.mxenv.PRIMARY_PYTHON": "python3",
             "core.mxenv.PYTHON_MIN_VERSION": "3.9",
             "core.mxenv.PYTHON_PACKAGE_INSTALLER": "pip",
-            "core.mxenv.UV_PYTHON": "",
+            "core.mxenv.UV_PYTHON": "$(PRIMARY_PYTHON)",
             "core.mxenv.VENV_ENABLED": "true",
             "core.mxenv.VENV_CREATE": "true",
             "core.mxenv.VENV_FOLDER": ".venv",

src/mxmake/topics/core/mxenv.mk

@@ -46,7 +46,7 @@
 #:  environments with global UV. Passed to `uv venv -p VALUE`. Supports version
 #:  specs like `3.11`, `3.14`, `cpython@3.14`. Defaults to PRIMARY_PYTHON value
 #:  for backward compatibility.
-#:default =
+#:default = $(PRIMARY_PYTHON)
 #:
 #:[setting.VENV_ENABLED]
 #:description = Flag whether to use virtual environment. If `false`, the
@@ -113,9 +113,6 @@ endif
 USE_GLOBAL_UV:=$(shell [[ "$(PYTHON_PACKAGE_INSTALLER)" == "uv" && "$(UV_AVAILABLE)" == "true" ]] && echo "true" || echo "false")
 USE_LOCAL_UV:=$(shell [[ "$(PYTHON_PACKAGE_INSTALLER)" == "uv" && "$(UV_AVAILABLE)" == "false" ]] && echo "true" || echo "false")
 
-# UV Python version (defaults to PRIMARY_PYTHON for backward compatibility)
-UV_PYTHON?=$(PRIMARY_PYTHON)
-
 # Check if global UV is outdated (non-blocking warning)
 ifeq ("$(USE_GLOBAL_UV)","true")
 UV_OUTDATED:=$(shell uv self update --dry-run 2>&1 | grep -q "Would update" && echo "true" || echo "false")