sphinx/pyfs plugins: add error messages for missing imports

hyde/ext/plugins/sphinx.py

@@ -20,13 +20,17 @@ from hyde.fs import File, Folder
 from hyde.model import Expando
 from hyde.ext.plugins.meta import MetaPlugin as _MetaPlugin
 
-import sphinx
-from sphinx.builders.html import JSONHTMLBuilder
-from sphinx.util.osutil import SEP
-
 from hyde.util import getLoggerWithNullHandler
 logger = getLoggerWithNullHandler('hyde.ext.plugins.sphinx')
 
+try:
+    import sphinx
+    from sphinx.builders.html import JSONHTMLBuilder
+    from sphinx.util.osutil import SEP
+except ImportError:
+    logger.error("The sphinx plugin requires sphinx.")
+    logger.error("`pip install -U sphinx` to get it.")
+    raise
 
 
 class SphinxPlugin(Plugin):

hyde/ext/publishers/pyfs.py

@@ -21,9 +21,14 @@ from hyde.util import getLoggerWithNullHandler
 logger = getLoggerWithNullHandler('hyde.ext.publishers.pyfs')
 
 
-from fs.osfs import OSFS
-from fs.path import pathjoin
-from fs.opener import fsopendir
+try:
+    from fs.osfs import OSFS
+    from fs.path import pathjoin
+    from fs.opener import fsopendir
+except ImportError:
+    logger.error("The PyFS publisher requires PyFilesystem v0.4 or later.")
+    logger.error("`pip install -U fs` to get it.")
+    raise