prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  NameError on del version when init has ImportError
  In `__init__.py`, `del version` gives `NameError` when `ImportError` happens.
  
  ```
  try:
      from .version import version as __version__
  except ImportError:
      __version__ = "unbuilt-dev"
  del version
  ```
  
  should be
  
  ```
  try:
      from .version import version as __version__
  except ImportError:
      __version__ = "unbuilt-dev"
  else:
      del version
  ```
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `skimage/__init__.py`
  Content:
  ```
  1 """Image Processing SciKit (Toolbox for SciPy)
  2 
  3 ``scikit-image`` (a.k.a. ``skimage``) is a collection of algorithms for image
  4 processing and computer vision.
  5 
  6 The main package of ``skimage`` only provides a few utilities for converting
  7 between image data types; for most features, you need to import one of the
  8 following subpackages:
  9 
  10 Subpackages
  11 -----------
  12 color
  13     Color space conversion.
  14 data
  15     Test images and example data.
  16 draw
  17     Drawing primitives (lines, text, etc.) that operate on NumPy arrays.
  18 exposure
  19     Image intensity adjustment, e.g., histogram equalization, etc.
  20 feature
  21     Feature detection and extraction, e.g., texture analysis corners, etc.
  22 filter
  23     Sharpening, edge finding, rank filters, thresholding, etc.
  24 graph
  25     Graph-theoretic operations, e.g., shortest paths.
  26 io
  27     Reading, saving, and displaying images and video.
  28 measure
  29     Measurement of image properties, e.g., similarity and contours.
  30 morphology
  31     Morphological operations, e.g., opening or skeletonization.
  32 novice
  33     Simplified interface for teaching purposes.
  34 restoration
  35     Restoration algorithms, e.g., deconvolution algorithms, denoising, etc.
  36 segmentation
  37     Partitioning an image into multiple regions.
  38 transform
  39     Geometric and other transforms, e.g., rotation or the Radon transform.
  40 util
  41     Generic utilities.
  42 viewer
  43     A simple graphical user interface for visualizing results and exploring
  44     parameters.
  45 
  46 Utility Functions
  47 -----------------
  48 img_as_float
  49     Convert an image to floating point format, with values in [0, 1].
  50 img_as_uint
  51     Convert an image to unsigned integer format, with values in [0, 65535].
  52 img_as_int
  53     Convert an image to signed integer format, with values in [-32768, 32767].
  54 img_as_ubyte
  55     Convert an image to unsigned byte format, with values in [0, 255].
  56 
  57 """
  58 
  59 import os.path as _osp
  60 import imp as _imp
  61 import functools as _functools
  62 import warnings as _warnings
  63 from skimage._shared.utils import deprecated as _deprecated
  64 
  65 pkg_dir = _osp.abspath(_osp.dirname(__file__))
  66 data_dir = _osp.join(pkg_dir, 'data')
  67 
  68 try:
  69     from .version import version as __version__
  70 except ImportError:
  71     __version__ = "unbuilt-dev"
  72 del version
  73 
  74 
  75 try:
  76     _imp.find_module('nose')
  77 except ImportError:
  78     def _test(verbose=False):
  79         """This would run all unit tests, but nose couldn't be
  80         imported so the test suite can not run.
  81         """
  82         raise ImportError("Could not load nose. Unit tests not available.")
  83 
  84     def _doctest(verbose=False):
  85         """This would run all doc tests, but nose couldn't be
  86         imported so the test suite can not run.
  87         """
  88         raise ImportError("Could not load nose. Doctests not available.")
  89 else:
  90     def _test(doctest=False, verbose=False):
  91         """Run all unit tests."""
  92         import nose
  93         args = ['', pkg_dir, '--exe', '--ignore-files=^_test']
  94         if verbose:
  95             args.extend(['-v', '-s'])
  96         if doctest:
  97             args.extend(['--with-doctest', '--ignore-files=^\.',
  98                          '--ignore-files=^setup\.py$$', '--ignore-files=test'])
  99             # Make sure warnings do not break the doc tests
  100             with _warnings.catch_warnings():
  101                 _warnings.simplefilter("ignore")
  102                 success = nose.run('skimage', argv=args)
  103         else:
  104             success = nose.run('skimage', argv=args)
  105         # Return sys.exit code
  106         if success:
  107             return 0
  108         else:
  109             return 1
  110 
  111 
  112 # do not use `test` as function name as this leads to a recursion problem with
  113 # the nose test suite
  114 test = _test
  115 test_verbose = _functools.partial(test, verbose=True)
  116 test_verbose.__doc__ = test.__doc__
  117 doctest = _functools.partial(test, doctest=True)
  118 doctest.__doc__ = doctest.__doc__
  119 doctest_verbose = _functools.partial(test, doctest=True, verbose=True)
  120 doctest_verbose.__doc__ = doctest.__doc__
  121 
  122 
  123 class _Log(Warning):
  124     pass
  125 
  126 
  127 class _FakeLog(object):
  128     def __init__(self, name):
  129         """
  130         Parameters
  131         ----------
  132         name : str
  133             Name of the log.
  134         repeat : bool
  135             Whether to print repeating messages more than once (False by
  136             default).
  137         """
  138         self._name = name
  139 
  140         warnings.simplefilter("always", _Log)
  141 
  142         self._warnings = _warnings
  143 
  144     def _warn(self, msg, wtype):
  145         self._warnings.warn('%s: %s' % (wtype, msg), _Log)
  146 
  147     def debug(self, msg):
  148         self._warn(msg, 'DEBUG')
  149 
  150     def info(self, msg):
  151         self._warn(msg, 'INFO')
  152 
  153     def warning(self, msg):
  154         self._warn(msg, 'WARNING')
  155 
  156     warn = warning
  157 
  158     def error(self, msg):
  159         self._warn(msg, 'ERROR')
  160 
  161     def critical(self, msg):
  162         self._warn(msg, 'CRITICAL')
  163 
  164     def addHandler(*args):
  165         pass
  166 
  167     def setLevel(*args):
  168         pass
  169 
  170 
  171 from .util.dtype import *
  172
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/skimage/__init__.py b/skimage/__init__.py
  --- a/skimage/__init__.py
  +++ b/skimage/__init__.py
  @@ -69,7 +69,8 @@
       from .version import version as __version__
   except ImportError:
       __version__ = "unbuilt-dev"
  -del version
  +else:
  +    del version
   
   
   try:
  
verification_info: {"golden_diff": "diff --git a/skimage/__init__.py b/skimage/__init__.py\n--- a/skimage/__init__.py\n+++ b/skimage/__init__.py\n@@ -69,7 +69,8 @@\n     from .version import version as __version__\n except ImportError:\n     __version__ = \"unbuilt-dev\"\n-del version\n+else:\n+    del version\n \n \n try:\n", "issue": "NameError on del version when init has ImportError\nIn `__init__.py`, `del version` gives `NameError` when `ImportError` happens.\n\n```\ntry:\n    from .version import version as __version__\nexcept ImportError:\n    __version__ = \"unbuilt-dev\"\ndel version\n```\n\nshould be\n\n```\ntry:\n    from .version import version as __version__\nexcept ImportError:\n    __version__ = \"unbuilt-dev\"\nelse:\n    del version\n```\n\n", "before_files": [{"content": "\"\"\"Image Processing SciKit (Toolbox for SciPy)\n\n``scikit-image`` (a.k.a. ``skimage``) is a collection of algorithms for image\nprocessing and computer vision.\n\nThe main package of ``skimage`` only provides a few utilities for converting\nbetween image data types; for most features, you need to import one of the\nfollowing subpackages:\n\nSubpackages\n-----------\ncolor\n    Color space conversion.\ndata\n    Test images and example data.\ndraw\n    Drawing primitives (lines, text, etc.) that operate on NumPy arrays.\nexposure\n    Image intensity adjustment, e.g., histogram equalization, etc.\nfeature\n    Feature detection and extraction, e.g., texture analysis corners, etc.\nfilter\n    Sharpening, edge finding, rank filters, thresholding, etc.\ngraph\n    Graph-theoretic operations, e.g., shortest paths.\nio\n    Reading, saving, and displaying images and video.\nmeasure\n    Measurement of image properties, e.g., similarity and contours.\nmorphology\n    Morphological operations, e.g., opening or skeletonization.\nnovice\n    Simplified interface for teaching purposes.\nrestoration\n    Restoration algorithms, e.g., deconvolution algorithms, denoising, etc.\nsegmentation\n    Partitioning an image into multiple regions.\ntransform\n    Geometric and other transforms, e.g., rotation or the Radon transform.\nutil\n    Generic utilities.\nviewer\n    A simple graphical user interface for visualizing results and exploring\n    parameters.\n\nUtility Functions\n-----------------\nimg_as_float\n    Convert an image to floating point format, with values in [0, 1].\nimg_as_uint\n    Convert an image to unsigned integer format, with values in [0, 65535].\nimg_as_int\n    Convert an image to signed integer format, with values in [-32768, 32767].\nimg_as_ubyte\n    Convert an image to unsigned byte format, with values in [0, 255].\n\n\"\"\"\n\nimport os.path as _osp\nimport imp as _imp\nimport functools as _functools\nimport warnings as _warnings\nfrom skimage._shared.utils import deprecated as _deprecated\n\npkg_dir = _osp.abspath(_osp.dirname(__file__))\ndata_dir = _osp.join(pkg_dir, 'data')\n\ntry:\n    from .version import version as __version__\nexcept ImportError:\n    __version__ = \"unbuilt-dev\"\ndel version\n\n\ntry:\n    _imp.find_module('nose')\nexcept ImportError:\n    def _test(verbose=False):\n        \"\"\"This would run all unit tests, but nose couldn't be\n        imported so the test suite can not run.\n        \"\"\"\n        raise ImportError(\"Could not load nose. Unit tests not available.\")\n\n    def _doctest(verbose=False):\n        \"\"\"This would run all doc tests, but nose couldn't be\n        imported so the test suite can not run.\n        \"\"\"\n        raise ImportError(\"Could not load nose. Doctests not available.\")\nelse:\n    def _test(doctest=False, verbose=False):\n        \"\"\"Run all unit tests.\"\"\"\n        import nose\n        args = ['', pkg_dir, '--exe', '--ignore-files=^_test']\n        if verbose:\n            args.extend(['-v', '-s'])\n        if doctest:\n            args.extend(['--with-doctest', '--ignore-files=^\\.',\n                         '--ignore-files=^setup\\.py$$', '--ignore-files=test'])\n            # Make sure warnings do not break the doc tests\n            with _warnings.catch_warnings():\n                _warnings.simplefilter(\"ignore\")\n                success = nose.run('skimage', argv=args)\n        else:\n            success = nose.run('skimage', argv=args)\n        # Return sys.exit code\n        if success:\n            return 0\n        else:\n            return 1\n\n\n# do not use `test` as function name as this leads to a recursion problem with\n# the nose test suite\ntest = _test\ntest_verbose = _functools.partial(test, verbose=True)\ntest_verbose.__doc__ = test.__doc__\ndoctest = _functools.partial(test, doctest=True)\ndoctest.__doc__ = doctest.__doc__\ndoctest_verbose = _functools.partial(test, doctest=True, verbose=True)\ndoctest_verbose.__doc__ = doctest.__doc__\n\n\nclass _Log(Warning):\n    pass\n\n\nclass _FakeLog(object):\n    def __init__(self, name):\n        \"\"\"\n        Parameters\n        ----------\n        name : str\n            Name of the log.\n        repeat : bool\n            Whether to print repeating messages more than once (False by\n            default).\n        \"\"\"\n        self._name = name\n\n        warnings.simplefilter(\"always\", _Log)\n\n        self._warnings = _warnings\n\n    def _warn(self, msg, wtype):\n        self._warnings.warn('%s: %s' % (wtype, msg), _Log)\n\n    def debug(self, msg):\n        self._warn(msg, 'DEBUG')\n\n    def info(self, msg):\n        self._warn(msg, 'INFO')\n\n    def warning(self, msg):\n        self._warn(msg, 'WARNING')\n\n    warn = warning\n\n    def error(self, msg):\n        self._warn(msg, 'ERROR')\n\n    def critical(self, msg):\n        self._warn(msg, 'CRITICAL')\n\n    def addHandler(*args):\n        pass\n\n    def setLevel(*args):\n        pass\n\n\nfrom .util.dtype import *\n", "path": "skimage/__init__.py"}], "after_files": [{"content": "\"\"\"Image Processing SciKit (Toolbox for SciPy)\n\n``scikit-image`` (a.k.a. ``skimage``) is a collection of algorithms for image\nprocessing and computer vision.\n\nThe main package of ``skimage`` only provides a few utilities for converting\nbetween image data types; for most features, you need to import one of the\nfollowing subpackages:\n\nSubpackages\n-----------\ncolor\n    Color space conversion.\ndata\n    Test images and example data.\ndraw\n    Drawing primitives (lines, text, etc.) that operate on NumPy arrays.\nexposure\n    Image intensity adjustment, e.g., histogram equalization, etc.\nfeature\n    Feature detection and extraction, e.g., texture analysis corners, etc.\nfilter\n    Sharpening, edge finding, rank filters, thresholding, etc.\ngraph\n    Graph-theoretic operations, e.g., shortest paths.\nio\n    Reading, saving, and displaying images and video.\nmeasure\n    Measurement of image properties, e.g., similarity and contours.\nmorphology\n    Morphological operations, e.g., opening or skeletonization.\nnovice\n    Simplified interface for teaching purposes.\nrestoration\n    Restoration algorithms, e.g., deconvolution algorithms, denoising, etc.\nsegmentation\n    Partitioning an image into multiple regions.\ntransform\n    Geometric and other transforms, e.g., rotation or the Radon transform.\nutil\n    Generic utilities.\nviewer\n    A simple graphical user interface for visualizing results and exploring\n    parameters.\n\nUtility Functions\n-----------------\nimg_as_float\n    Convert an image to floating point format, with values in [0, 1].\nimg_as_uint\n    Convert an image to unsigned integer format, with values in [0, 65535].\nimg_as_int\n    Convert an image to signed integer format, with values in [-32768, 32767].\nimg_as_ubyte\n    Convert an image to unsigned byte format, with values in [0, 255].\n\n\"\"\"\n\nimport os.path as _osp\nimport imp as _imp\nimport functools as _functools\nimport warnings as _warnings\nfrom skimage._shared.utils import deprecated as _deprecated\n\npkg_dir = _osp.abspath(_osp.dirname(__file__))\ndata_dir = _osp.join(pkg_dir, 'data')\n\ntry:\n    from .version import version as __version__\nexcept ImportError:\n    __version__ = \"unbuilt-dev\"\nelse:\n    del version\n\n\ntry:\n    _imp.find_module('nose')\nexcept ImportError:\n    def _test(verbose=False):\n        \"\"\"This would run all unit tests, but nose couldn't be\n        imported so the test suite can not run.\n        \"\"\"\n        raise ImportError(\"Could not load nose. Unit tests not available.\")\n\n    def _doctest(verbose=False):\n        \"\"\"This would run all doc tests, but nose couldn't be\n        imported so the test suite can not run.\n        \"\"\"\n        raise ImportError(\"Could not load nose. Doctests not available.\")\nelse:\n    def _test(doctest=False, verbose=False):\n        \"\"\"Run all unit tests.\"\"\"\n        import nose\n        args = ['', pkg_dir, '--exe', '--ignore-files=^_test']\n        if verbose:\n            args.extend(['-v', '-s'])\n        if doctest:\n            args.extend(['--with-doctest', '--ignore-files=^\\.',\n                         '--ignore-files=^setup\\.py$$', '--ignore-files=test'])\n            # Make sure warnings do not break the doc tests\n            with _warnings.catch_warnings():\n                _warnings.simplefilter(\"ignore\")\n                success = nose.run('skimage', argv=args)\n        else:\n            success = nose.run('skimage', argv=args)\n        # Return sys.exit code\n        if success:\n            return 0\n        else:\n            return 1\n\n\n# do not use `test` as function name as this leads to a recursion problem with\n# the nose test suite\ntest = _test\ntest_verbose = _functools.partial(test, verbose=True)\ntest_verbose.__doc__ = test.__doc__\ndoctest = _functools.partial(test, doctest=True)\ndoctest.__doc__ = doctest.__doc__\ndoctest_verbose = _functools.partial(test, doctest=True, verbose=True)\ndoctest_verbose.__doc__ = doctest.__doc__\n\n\nclass _Log(Warning):\n    pass\n\n\nclass _FakeLog(object):\n    def __init__(self, name):\n        \"\"\"\n        Parameters\n        ----------\n        name : str\n            Name of the log.\n        repeat : bool\n            Whether to print repeating messages more than once (False by\n            default).\n        \"\"\"\n        self._name = name\n\n        warnings.simplefilter(\"always\", _Log)\n\n        self._warnings = _warnings\n\n    def _warn(self, msg, wtype):\n        self._warnings.warn('%s: %s' % (wtype, msg), _Log)\n\n    def debug(self, msg):\n        self._warn(msg, 'DEBUG')\n\n    def info(self, msg):\n        self._warn(msg, 'INFO')\n\n    def warning(self, msg):\n        self._warn(msg, 'WARNING')\n\n    warn = warning\n\n    def error(self, msg):\n        self._warn(msg, 'ERROR')\n\n    def critical(self, msg):\n        self._warn(msg, 'CRITICAL')\n\n    def addHandler(*args):\n        pass\n\n    def setLevel(*args):\n        pass\n\n\nfrom .util.dtype import *\n", "path": "skimage/__init__.py"}]}