Added build location checker, does not fully work yet. Complicated error.

skimage/__check_build/README

@@ -0,0 +1,34 @@
+Files in this directory are derived from the scikit-learn project with the
+following license:
+
+New BSD License
+
+Copyright (c) 2007–2014 The scikit-learn developers.
+All rights reserved.
+
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+  a. Redistributions of source code must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+  b. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in the
+     documentation and/or other materials provided with the distribution.
+  c. Neither the name of the Scikit-learn Developers  nor the names of
+     its contributors may be used to endorse or promote products
+     derived from this software without specific prior written
+     permission. 
+
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+    ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+    DAMAGE.

skimage/__check_build/__init__.py

@@ -0,0 +1,47 @@
+""" Module to give helpful messages to the user that did not
+compile scikit-image properly.
+This checking code was stolen from scikit-learn & pyart.
+"""
+import os
+
+INPLACE_MSG = """
+It appears that you are importing a local scikit-image source tree. For
+this, you need to have an inplace install. Maybe you are in the source
+directory and you need to try from another location."""
+
+STANDARD_MSG = """
+If you have used an installer, please check that it is suited for your
+Python version, your operating system and your platform."""
+
+
+def raise_build_error(e):
+    # Raise a comprehensible error and list the contents of the
+    # directory to help debugging on the mailing list.
+    local_dir = os.path.split(__file__)[0]
+    msg = STANDARD_MSG
+    if local_dir == "skimage/__check_build":
+        # Picking up the local install: this will work only if the
+        # install is an 'inplace build'
+        msg = INPLACE_MSG
+    dir_content = list()
+    for i, filename in enumerate(os.listdir(local_dir)):
+        if ((i + 1) % 3):
+            dir_content.append(filename.ljust(26))
+        else:
+            dir_content.append(filename + '\n')
+    raise ImportError("""%s
+___________________________________________________________________________
+Contents of %s:
+%s
+___________________________________________________________________________
+It seems that scikit-image has not been built correctly.
+
+If you have installed scikit-image from source, please do not forget
+to build the package before using it: run `python setup.py install` or
+`make` in the source directory.
+%s""" % (e, local_dir, ''.join(dir_content).strip(), msg))
+
+try:
+    from ._check_build import check_build
+except ImportError as e:
+    raise_build_error(e)

skimage/__check_build/_check_build.pyx

@@ -0,0 +1,2 @@
+def check_build():
+    return

skimage/__check_build/setup.py

@@ -0,0 +1,19 @@
+# Author: Virgile Fritsch <virgile.fritsch@inria.fr>
+# License: BSD 3 clause
+
+import numpy
+from skimage._build import cython
+
+def configuration(parent_package='', top_path=None):
+    from numpy.distutils.misc_util import Configuration
+
+    config = Configuration('__check_build', parent_package, top_path)
+
+    cython(['_check_build.pyx'], working_path=base_path)
+    config.add_extension('_check_build',
+                         sources=['_check_build.c'])
+    return config
+
+if __name__ == '__main__':
+    from numpy.distutils.core import setup
+    setup(**configuration(top_path='').todict())

skimage/__init__.py

@@ -110,3 +110,5 @@ doctest_verbose = functools.partial(test, doctest=True, verbose=True)
 doctest_verbose.__doc__ = doctest.__doc__
 
 del warnings, functools, osp, imp
+
+from . import __check_build

skimage/setup.py

@@ -6,6 +6,7 @@ def configuration(parent_package='', top_path=None):
 
     config = Configuration('skimage', parent_package, top_path)
 
+    config.add_subpackage('__check_build')
     config.add_subpackage('_shared')
     config.add_subpackage('color')
     config.add_subpackage('data')