# HG changeset patch
# User Ludovic Chabant <ludovic@chabant.com>
# Date 1417726193 28800
# Node ID 1c3d229158ba79f289356efdfd1bf013e222a11e
# Parent  8d956bd94ad250af1bcf59eb5449f5ebdf562d17
Make a nice error message when a layout hasn't been found.

diff -r 8d956bd94ad2 -r 1c3d229158ba piecrust/rendering.py
--- a/piecrust/rendering.py	Thu Dec 04 12:49:35 2014 -0800
+++ b/piecrust/rendering.py	Thu Dec 04 12:49:53 2014 -0800
@@ -4,7 +4,7 @@
 from piecrust.data.builder import (DataBuildingContext, build_page_data,
         build_layout_data)
 from piecrust.sources.base import PageSource
-from piecrust.templating.base import TemplatingError
+from piecrust.templating.base import TemplateNotFoundError, TemplatingError
 from piecrust.uriutil import get_slug
 
 
@@ -205,7 +205,12 @@
     engine = get_template_engine(page.app, engine_name)
     if engine is None:
         raise PageRenderingError("No such template engine: %s" % engine_name)
-    output = engine.renderFile(full_names, layout_data)
+    try:
+        output = engine.renderFile(full_names, layout_data)
+    except TemplateNotFoundError as ex:
+        msg = "Can't find template for page: %s\n" % page.path
+        msg += "Looked for: %s" % ', '.join(full_names)
+        raise Exception(msg) from ex
     return output