build: always re-generate PRODUCT_VERSION

build.bat

@@ -15,17 +15,15 @@ if not defined VERSION_PATCH set VERSION_PATCH=1
 if not defined WEASEL_VERSION set WEASEL_VERSION=%VERSION_MAJOR%.%VERSION_MINOR%.%VERSION_PATCH%
 if not defined WEASEL_BUILD set WEASEL_BUILD=0
 
-if not defined PRODUCT_VERSION (
-  rem use numeric build version for release build
-  set PRODUCT_VERSION=%WEASEL_VERSION%.%WEASEL_BUILD%
-  rem for non-release build, try to use git commit hash as product build version
-  if not defined RELEASE_BUILD (
-    rem check if git is installed and available, then get the short commit id of head
-    git --version >nul 2>&1
-    if not errorlevel 1 (
-      rem get short commmit id of head
-      for /F %%i in ('git rev-parse --short HEAD') do (set PRODUCT_VERSION=%WEASEL_VERSION%-%%i)
-    )
+rem use numeric build version for release build
+set PRODUCT_VERSION=%WEASEL_VERSION%.%WEASEL_BUILD%
+rem for non-release build, try to use git commit hash as product build version
+if not defined RELEASE_BUILD (
+  rem check if git is installed and available, then get the short commit id of head
+  git --version >nul 2>&1
+  if not errorlevel 1 (
+    rem get short commmit id of head
+    for /F %%i in ('git rev-parse --short HEAD') do (set PRODUCT_VERSION=%WEASEL_VERSION%-%%i)
   )
 )