old_contents: #!env python
  import os
  import sys
  import subprocess
  
  # A quick Python implementation of unix 'where' command.
  def where(exeName):
      searchPath = os.getenv("PATH")
      paths = searchPath.split(";" if sys.platform == "win32" else ":")
      for path in paths:
          candidatePath = os.path.join(path, exeName)
          if os.path.exists(candidatePath):
              return candidatePath
      return None
  
  def findModules(path):
      result = []
      for entry in os.scandir(path):
          if entry.is_dir() and os.path.exists(os.path.join(path, entry.name, "__init__.py")):
              result.append(entry.name)
      return result
  
  def main():
      if sys.platform == "win32":
          os.putenv("MYPYPATH", r".;.\plugins;.\plugins\VersionUpgrade;..\Uranium\;..\Uranium\stubs\\" )
      else:
          os.putenv("MYPYPATH", r".:./plugins:./plugins/VersionUpgrade:../Uranium/:../Uranium\stubs/")
  
      # Mypy really needs to be run via its Python script otherwise it can't find its data files.
      mypyExe = where("mypy.bat" if sys.platform == "win32" else "mypy")
      mypyModule = os.path.join(os.path.dirname(mypyExe), "mypy")
  
      plugins = findModules("plugins")
      plugins.sort()
  
      mods = ["cura"] + plugins + findModules("plugins/VersionUpgrade")
  
      for mod in mods:
          print("------------- Checking module {mod}".format(**locals()))
          result = subprocess.run([sys.executable, mypyModule, "-p", mod])
          if result.returncode != 0:
              print("""
      Module {mod} failed checking. :(
      """.format(**locals()))
              break
      else:
          print("""
  
      Done checking. All is good.
      """)
      return 0
  sys.exit(main())
  
new_contents: #!env python
  import os
  import sys
  import subprocess
  
  # A quick Python implementation of unix 'where' command.
  def where(exeName, searchPath=os.getenv("PATH")):
      paths = searchPath.split(";" if sys.platform == "win32" else ":")
      for path in paths:
          candidatePath = os.path.join(path, exeName)
          if os.path.exists(candidatePath):
              return candidatePath
      return None
  
  def findModules(path):
      result = []
      for entry in os.scandir(path):
          if entry.is_dir() and os.path.exists(os.path.join(path, entry.name, "__init__.py")):
              result.append(entry.name)
      return result
  
  def main():
      # Find Uranium via the PYTHONPATH var
      uraniumUMPath = where("UM", os.getenv("PYTHONPATH"))
      if uraniumUMPath is None:
          uraniumUMPath = os.path.join("..", "Uranium")
      uraniumPath = os.path.dirname(uraniumUMPath)
  
      mypyPathParts = [".", os.path.join(".", "plugins"), os.path.join(".", "plugins", "VersionUpgrade"),
                       uraniumPath, os.path.join(uraniumPath, "stubs")]
      if sys.platform == "win32":
          os.putenv("MYPYPATH", ";".join(mypyPathParts))
      else:
          os.putenv("MYPYPATH", ":".join(mypyPathParts))
  
      # Mypy really needs to be run via its Python script otherwise it can't find its data files.
      mypyExe = where("mypy.bat" if sys.platform == "win32" else "mypy")
      mypyModule = os.path.join(os.path.dirname(mypyExe), "mypy")
  
      plugins = findModules("plugins")
      plugins.sort()
  
      mods = ["cura"] + plugins + findModules("plugins/VersionUpgrade")
  
      for mod in mods:
          print("------------- Checking module {mod}".format(**locals()))
          result = subprocess.run([sys.executable, mypyModule, "-p", mod])
          if result.returncode != 0:
              print("""
      Module {mod} failed checking. :(
      """.format(**locals()))
              break
      else:
          print("""
  
      Done checking. All is good.
      """)
      return 0
  sys.exit(main())
  
subject: Make the run_mypy.py script find Uranium via the PYTHONPATH env var.