remove strict arg from css_js_prerelease

setup.py

@@ -214,9 +214,8 b' class UploadWindowsInstallers(upload):'
 
 setup_args['cmdclass'] = {
     'build_py': css_js_prerelease(
-            check_package_data_first(git_prebuild('IPython')),
-        strict=False),
-    'sdist' : css_js_prerelease(git_prebuild('IPython', sdist), strict=False),
+            check_package_data_first(git_prebuild('IPython'))),
+    'sdist' : css_js_prerelease(git_prebuild('IPython', sdist)),
     'upload_wininst' : UploadWindowsInstallers,
     'submodule' : UpdateSubmodules,
     'css' : CompileCSS,
@@ -284,7 +283,7 b" if 'setuptools' in sys.modules:"
     # setup.py develop should check for submodules
     from setuptools.command.develop import develop
     setup_args['cmdclass']['develop'] = require_submodules(develop)
-    setup_args['cmdclass']['bdist_wheel'] = css_js_prerelease(get_bdist_wheel(), strict=False)
+    setup_args['cmdclass']['bdist_wheel'] = css_js_prerelease(get_bdist_wheel())
     
     setuptools_extra_args['zip_safe'] = False
     setuptools_extra_args['entry_points'] = {'console_scripts':find_entry_points()}

setupbase.py

@@ -746,7 +746,7 b' class JavascriptVersion(Command):'
                 f.write(line)
 
 
-def css_js_prerelease(command, strict=True):
+def css_js_prerelease(command):
     """decorator for building js/minified css prior to a release"""
     class DecoratedCommand(command):
         def run(self):
@@ -756,10 +756,7 b' def css_js_prerelease(command, strict=True):'
             try:
                 self.distribution.run_command('css')
             except Exception as e:
-                if strict:
-                    raise
-                else:
-                    log.warn("rebuilding css and sourcemaps failed (not a problem)")
-                    log.warn(str(e))
+                log.warn("rebuilding css and sourcemaps failed (not a problem)")
+                log.warn(str(e))
             command.run(self)
     return DecoratedCommand