Remove error-chain

Closes #576

Cargo.lock

@@ -342,6 +342,7 @@ dependencies = [
  "serde_derive 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
  "syntect 3.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "utils 0.1.0",
 ]
 
 [[package]]
@@ -616,7 +617,6 @@ dependencies = [
 name = "errors"
 version = "0.1.0"
 dependencies = [
- "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.20.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "syntect 3.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "tera 0.11.20 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2229,7 +2229,6 @@ dependencies = [
  "base64 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "config 0.1.0",
  "csv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "errors 0.1.0",
  "imageproc 0.1.0",
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",

components/config/Cargo.toml

@@ -13,3 +13,4 @@ lazy_static = "1"
 syntect = "3"
 
 errors = { path = "../errors" }
+utils = { path = "../utils" }

components/config/src/config.rs

@@ -1,6 +1,4 @@
 use std::collections::HashMap;
-use std::fs::File;
-use std::io::prelude::*;
 use std::path::{Path, PathBuf};
 
 use chrono::Utc;
@@ -9,9 +7,10 @@ use syntect::parsing::{SyntaxSet, SyntaxSetBuilder};
 use toml;
 use toml::Value as Toml;
 
-use errors::{Result, ResultExt};
+use errors::Result;
 use highlighting::THEME_SET;
 use theme::Theme;
+use utils::fs::read_file_with_error;
 
 // We want a default base url for tests
 static DEFAULT_BASE_URL: &'static str = "http://a-website.com";
@@ -66,7 +65,13 @@ impl Taxonomy {
 
 impl Default for Taxonomy {
     fn default() -> Taxonomy {
-        Taxonomy { name: String::new(), paginate_by: None, paginate_path: None, rss: false, lang: None }
+        Taxonomy {
+            name: String::new(),
+            paginate_by: None,
+            paginate_path: None,
+            rss: false,
+            lang: None,
+        }
     }
 }
 
@@ -172,15 +177,12 @@ impl Config {
 
     /// Parses a config file from the given path
     pub fn from_file<P: AsRef<Path>>(path: P) -> Result<Config> {
-        let mut content = String::new();
         let path = path.as_ref();
         let file_name = path.file_name().unwrap();
-        File::open(path)
-            .chain_err(|| {
-                format!("No `{:?}` file found. Are you in the right directory?", file_name)
-            })?
-            .read_to_string(&mut content)?;
-
+        let content = read_file_with_error(
+            path,
+            &format!("No `{:?}` file found. Are you in the right directory?", file_name),
+        )?;
         Config::parse(&content)
     }
 

components/config/src/lib.rs

@@ -1,14 +1,16 @@
 #[macro_use]
 extern crate serde_derive;
-extern crate toml;
-#[macro_use]
-extern crate errors;
 extern crate chrono;
 extern crate globset;
+extern crate toml;
 #[macro_use]
 extern crate lazy_static;
 extern crate syntect;
 
+#[macro_use]
+extern crate errors;
+extern crate utils;
+
 mod config;
 pub mod highlighting;
 mod theme;

components/config/src/theme.rs

@@ -1,11 +1,10 @@
 use std::collections::HashMap;
-use std::fs::File;
-use std::io::prelude::*;
 use std::path::PathBuf;
 
 use toml::Value as Toml;
 
-use errors::{Result, ResultExt};
+use errors::Result;
+use utils::fs::read_file_with_error;
 
 /// Holds the data from a `theme.toml` file.
 /// There are other fields than `extra` in it but Zola
@@ -40,15 +39,12 @@ impl Theme {
 
     /// Parses a theme file from the given path
     pub fn from_file(path: &PathBuf) -> Result<Theme> {
-        let mut content = String::new();
-        File::open(path)
-            .chain_err(|| {
+        let content = read_file_with_error(
+            path,
             "No `theme.toml` file found. \
              Is the `theme` defined in your `config.toml present in the `themes` directory \
-                 and does it have a `theme.toml` inside?"
-            })?
-            .read_to_string(&mut content)?;
-
+             and does it have a `theme.toml` inside?",
+        )?;
         Theme::parse(&content)
     }
 }

components/errors/Cargo.toml

@@ -4,7 +4,6 @@ version = "0.1.0"
 authors = ["Vincent Prouillet <prouillet.vincent@gmail.com>"]
 
 [dependencies]
-error-chain = "0.12"
 tera = "0.11"
 toml = "0.4"
 image = "0.20"

components/errors/src/lib.rs

@@ -1,27 +1,102 @@
-#![allow(unused_doc_comments)]
-
-#[macro_use]
-extern crate error_chain;
 extern crate image;
 extern crate syntect;
 extern crate tera;
 extern crate toml;
 
-error_chain! {
-    errors {}
+use std::convert::Into;
+use std::error::Error as StdError;
+use std::fmt;
 
-    links {
-        Tera(tera::Error, tera::ErrorKind);
-    }
+#[derive(Debug)]
+pub enum ErrorKind {
+    Msg(String),
+    Tera(tera::Error),
+    Io(::std::io::Error),
+    Toml(toml::de::Error),
+    Image(image::ImageError),
+    Syntect(syntect::LoadingError),
+}
 
-    foreign_links {
-        Io(::std::io::Error);
-        Toml(toml::de::Error);
-        Image(image::ImageError);
-        Syntect(syntect::LoadingError);
+/// The Error type
+#[derive(Debug)]
+pub struct Error {
+    /// Kind of error
+    pub kind: ErrorKind,
+    pub source: Option<Box<dyn StdError>>,
+}
+unsafe impl Sync for Error {}
+unsafe impl Send for Error {}
+
+impl StdError for Error {
+    fn source(&self) -> Option<&(dyn StdError + 'static)> {
+        self.source.as_ref().map(|c| &**c)
     }
 }
 
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self.kind {
+            ErrorKind::Msg(ref message) => write!(f, "{}", message),
+            ErrorKind::Tera(ref e) => write!(f, "{}", e),
+            ErrorKind::Io(ref e) => write!(f, "{}", e),
+            ErrorKind::Toml(ref e) => write!(f, "{}", e),
+            ErrorKind::Image(ref e) => write!(f, "{}", e),
+            ErrorKind::Syntect(ref e) => write!(f, "{}", e),
+        }
+    }
+}
+
+impl Error {
+    /// Creates generic error
+    pub fn msg(value: impl ToString) -> Self {
+        Self { kind: ErrorKind::Msg(value.to_string()), source: None }
+    }
+
+    /// Creates generic error with a cause
+    pub fn chain(value: impl ToString, source: impl Into<Box<dyn StdError>>) -> Self {
+        Self { kind: ErrorKind::Msg(value.to_string()), source: Some(source.into()) }
+    }
+}
+
+
+impl From<&str> for Error {
+    fn from(e: &str) -> Self {
+        Self::msg(e)
+    }
+}
+impl From<String> for Error {
+    fn from(e: String) -> Self {
+        Self::msg(e)
+    }
+}
+impl From<toml::de::Error> for Error {
+    fn from(e: toml::de::Error) -> Self {
+        Self { kind: ErrorKind::Toml(e), source: None }
+    }
+}
+impl From<syntect::LoadingError> for Error {
+    fn from(e: syntect::LoadingError) -> Self {
+        Self { kind: ErrorKind::Syntect(e), source: None }
+    }
+}
+impl From<tera::Error> for Error {
+    fn from(e: tera::Error) -> Self {
+        Self { kind: ErrorKind::Tera(e), source: None }
+    }
+}
+impl From<::std::io::Error> for Error {
+    fn from(e: ::std::io::Error) -> Self {
+        Self { kind: ErrorKind::Io(e), source: None }
+    }
+}
+impl From<image::ImageError> for Error {
+    fn from(e: image::ImageError) -> Self {
+        Self { kind: ErrorKind::Image(e), source: None }
+    }
+}
+/// Convenient wrapper around std::Result.
+pub type Result<T> = ::std::result::Result<T, Error>;
+
 // So we can use bail! in all other crates
 #[macro_export]
 macro_rules! bail {

components/front_matter/src/lib.rs

@@ -12,7 +12,7 @@ extern crate toml;
 extern crate errors;
 extern crate utils;
 
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 use regex::Regex;
 use std::path::Path;
 
@@ -71,8 +71,8 @@ pub fn split_section_content(
     content: &str,
 ) -> Result<(SectionFrontMatter, String)> {
     let (front_matter, content) = split_content(file_path, content)?;
-    let meta = SectionFrontMatter::parse(&front_matter).chain_err(|| {
-        format!("Error when parsing front matter of section `{}`", file_path.to_string_lossy())
+    let meta = SectionFrontMatter::parse(&front_matter).map_err(|e| {
+        Error::chain(format!("Error when parsing front matter of section `{}`", file_path.to_string_lossy()), e)
     })?;
     Ok((meta, content))
 }
@@ -81,8 +81,8 @@ pub fn split_section_content(
 /// Returns a parsed `PageFrontMatter` and the rest of the content
 pub fn split_page_content(file_path: &Path, content: &str) -> Result<(PageFrontMatter, String)> {
     let (front_matter, content) = split_content(file_path, content)?;
-    let meta = PageFrontMatter::parse(&front_matter).chain_err(|| {
-        format!("Error when parsing front matter of page `{}`", file_path.to_string_lossy())
+    let meta = PageFrontMatter::parse(&front_matter).map_err(|e| {
+        Error::chain(format!("Error when parsing front matter of page `{}`", file_path.to_string_lossy()), e)
     })?;
     Ok((meta, content))
 }

components/imageproc/src/lib.rs

@@ -20,7 +20,7 @@ use image::{FilterType, GenericImageView};
 use rayon::prelude::*;
 use regex::Regex;
 
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 use utils::fs as ufs;
 
 static RESIZED_SUBDIR: &'static str = "processed_images";
@@ -456,7 +456,7 @@ impl Processor {
                 let target =
                     self.resized_path.join(Self::op_filename(*hash, op.collision_id, op.format));
                 op.perform(&self.content_path, &target)
-                    .chain_err(|| format!("Failed to process image: {}", op.source))
+                    .map_err(|e| Error::chain(format!("Failed to process image: {}", op.source), e))
             })
             .collect::<Result<()>>()
     }

components/library/src/content/page.rs

@@ -8,7 +8,7 @@ use slug::slugify;
 use tera::{Context as TeraContext, Tera};
 
 use config::Config;
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 use front_matter::{split_page_content, InsertAnchor, PageFrontMatter};
 use library::Library;
 use rendering::{render_content, Header, RenderContext};
@@ -234,7 +234,7 @@ impl Page {
         context.tera_context.insert("page", &SerializingPage::from_page_basic(self, None));
 
         let res = render_content(&self.raw_content, &context)
-            .chain_err(|| format!("Failed to render content of {}", self.file.path.display()))?;
+            .map_err(|e| Error::chain(format!("Failed to render content of {}", self.file.path.display()), e))?;
 
         self.summary = res.summary_len.map(|l| res.body[0..l].to_owned());
         self.content = res.body;
@@ -258,7 +258,7 @@ impl Page {
         context.insert("lang", &self.lang);
 
         render_template(&tpl_name, tera, &context, &config.theme)
-            .chain_err(|| format!("Failed to render page '{}'", self.file.path.display()))
+            .map_err(|e| Error::chain(format!("Failed to render page '{}'", self.file.path.display()), e))
     }
 
     /// Creates a vectors of asset URLs.

components/library/src/content/section.rs

@@ -5,7 +5,7 @@ use slotmap::Key;
 use tera::{Context as TeraContext, Tera};
 
 use config::Config;
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 use front_matter::{split_section_content, SectionFrontMatter};
 use rendering::{render_content, Header, RenderContext};
 use utils::fs::{find_related_assets, read_file};
@@ -172,7 +172,7 @@ impl Section {
         context.tera_context.insert("section", &SerializingSection::from_section_basic(self, None));
 
         let res = render_content(&self.raw_content, &context)
-            .chain_err(|| format!("Failed to render content of {}", self.file.path.display()))?;
+            .map_err(|e| Error::chain(format!("Failed to render content of {}", self.file.path.display()), e))?;
         self.content = res.body;
         self.toc = res.toc;
         Ok(())
@@ -190,7 +190,7 @@ impl Section {
         context.insert("lang", &self.lang);
 
         render_template(tpl_name, tera, &context, &config.theme)
-            .chain_err(|| format!("Failed to render section '{}'", self.file.path.display()))
+            .map_err(|e| Error::chain(format!("Failed to render section '{}'", self.file.path.display()), e))
     }
 
     /// Is this the index section?

components/library/src/pagination/mod.rs

@@ -4,7 +4,7 @@ use slotmap::Key;
 use tera::{to_value, Context, Tera, Value};
 
 use config::Config;
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 use utils::templates::render_template;
 
 use content::{Section, SerializingPage, SerializingSection};
@@ -222,7 +222,7 @@ impl<'a> Paginator<'a> {
         context.insert("paginator", &self.build_paginator_context(pager));
 
         render_template(&self.template, tera, &context, &config.theme)
-            .chain_err(|| format!("Failed to render pager {}", pager.index))
+            .map_err(|e| Error::chain(format!("Failed to render pager {}", pager.index), e))
     }
 }
 

components/library/src/taxonomies/mod.rs

@@ -5,7 +5,7 @@ use slug::slugify;
 use tera::{Context, Tera};
 
 use config::{Config, Taxonomy as TaxonomyConfig};
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 use utils::templates::render_template;
 
 use content::SerializingPage;
@@ -145,7 +145,7 @@ impl Taxonomy {
         context.insert("current_path", &format!("/{}/{}", self.kind.name, item.slug));
 
         render_template(&format!("{}/single.html", self.kind.name), tera, &context, &config.theme)
-            .chain_err(|| format!("Failed to render single term {} page.", self.kind.name))
+            .map_err(|e| Error::chain(format!("Failed to render single term {} page.", self.kind.name), e))
     }
 
     pub fn render_all_terms(
@@ -164,7 +164,7 @@ impl Taxonomy {
         context.insert("current_path", &self.kind.name);
 
         render_template(&format!("{}/list.html", self.kind.name), tera, &context, &config.theme)
-            .chain_err(|| format!("Failed to render a list of {} page.", self.kind.name))
+            .map_err(|e| Error::chain(format!("Failed to render a list of {} page.", self.kind.name), e))
     }
 
     pub fn to_serialized<'a>(&'a self, library: &'a Library) -> SerializedTaxonomy<'a> {
@@ -334,7 +334,7 @@ mod tests {
         let err = taxonomies.unwrap_err();
         // no path as this is created by Default
         assert_eq!(
-            err.description(),
+            format!("{}", err),
             "Page `` has taxonomy `tags` which is not defined in config.toml"
         );
     }
@@ -442,7 +442,7 @@ mod tests {
         let err = taxonomies.unwrap_err();
         // no path as this is created by Default
         assert_eq!(
-            err.description(),
+            format!("{}", err),
             "Page `` has taxonomy `tags` which is not available in that language"
         );
     }

components/rendering/src/shortcode.rs

@@ -4,7 +4,7 @@ use regex::Regex;
 use tera::{to_value, Context, Map, Value};
 
 use context::RenderContext;
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 
 // This include forces recompiling this source file if the grammar file changes.
 // Uncomment it when doing changes to the .pest file
@@ -116,7 +116,7 @@ fn render_shortcode(
     let res = context
         .tera
         .render(&tpl_name, &tera_context)
-        .chain_err(|| format!("Failed to render {} shortcode", name))?;
+        .map_err(|e| Error::chain(format!("Failed to render {} shortcode", name), e))?;
 
     // Small hack to avoid having multiple blank lines because of Tera tags for example
     // A blank like will cause the markdown parser to think we're out of HTML and start looking

components/rendering/tests/markdown.rs

@@ -660,7 +660,7 @@ fn can_show_error_message_for_invalid_external_links() {
     let res = render_content("[a link](http://google.comy)", &context);
     assert!(res.is_err());
     let err = res.unwrap_err();
-    assert!(err.description().contains("Link http://google.comy is not valid"));
+    assert!(format!("{}", err).contains("Link http://google.comy is not valid"));
 }
 
 #[test]

components/site/src/lib.rs

@@ -30,7 +30,7 @@ use sass_rs::{compile_file, Options as SassOptions, OutputStyle};
 use tera::{Context, Tera};
 
 use config::{get_config, Config};
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 use front_matter::InsertAnchor;
 use library::{
     find_taxonomies, sort_actual_pages_by_date, Library, Page, Paginator, Section, Taxonomy,
@@ -87,7 +87,7 @@ impl Site {
             format!("{}/{}", path.to_string_lossy().replace("\\", "/"), "templates/**/*.*ml");
         // Only parsing as we might be extending templates from themes and that would error
         // as we haven't loaded them yet
-        let mut tera = Tera::parse(&tpl_glob).chain_err(|| "Error parsing templates")?;
+        let mut tera = Tera::parse(&tpl_glob).map_err(|e| Error::chain("Error parsing templates", e))?;
         if let Some(theme) = config.theme.clone() {
             // Grab data from the extra section of the theme
             config.merge_with_theme(&path.join("themes").join(&theme).join("theme.toml"))?;
@@ -104,9 +104,9 @@ impl Site {
                 format!("themes/{}/templates/**/*.*ml", theme)
             );
             let mut tera_theme =
-                Tera::parse(&theme_tpl_glob).chain_err(|| "Error parsing templates from themes")?;
+                Tera::parse(&theme_tpl_glob).map_err(|e| Error::chain("Error parsing templates from themes", e))?;
             rewrite_theme_paths(&mut tera_theme, &theme);
-            // TODO: same as below
+            // TODO: we do that twice, make it dry?
             if theme_path.join("templates").join("robots.txt").exists() {
                 tera_theme
                     .add_template_file(theme_path.join("templates").join("robots.txt"), None)?;
@@ -470,7 +470,7 @@ impl Site {
     pub fn clean(&self) -> Result<()> {
         if self.output_path.exists() {
             // Delete current `public` directory so we can start fresh
-            remove_dir_all(&self.output_path).chain_err(|| "Couldn't delete output directory")?;
+            remove_dir_all(&self.output_path).map_err(|e| Error::chain("Couldn't delete output directory", e))?;
         }
 
         Ok(())

components/templates/Cargo.toml

@@ -11,7 +11,6 @@ pulldown-cmark = "0.2"
 toml = "0.4"
 csv = "1"
 serde_json = "1.0"
-error-chain = "0.12"
 reqwest = "0.9"
 url = "1.5"
 

components/templates/src/global_fns/mod.rs

@@ -1,5 +1,3 @@
-extern crate error_chain;
-
 use std::collections::HashMap;
 use std::sync::{Arc, Mutex};
 

components/templates/src/lib.rs

@@ -25,7 +25,7 @@ pub mod global_fns;
 
 use tera::{Context, Tera};
 
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 
 lazy_static! {
     pub static ref ZOLA_TERA: Tera = {
@@ -57,5 +57,5 @@ pub fn render_redirect_template(url: &str, tera: &Tera) -> Result<String> {
     context.insert("url", &url);
 
     tera.render("internal/alias.html", &context)
-        .chain_err(|| format!("Failed to render alias for '{}'", url))
+        .map_err(|e| Error::chain(format!("Failed to render alias for '{}'", url), e))
 }

components/utils/src/fs.rs

@@ -4,7 +4,7 @@ use std::path::{Path, PathBuf};
 use std::time::SystemTime;
 use walkdir::WalkDir;
 
-use errors::{Result, ResultExt};
+use errors::{Result, Error};
 
 pub fn is_path_in_directory(parent: &Path, path: &Path) -> Result<bool> {
     let canonical_path = path
@@ -19,7 +19,8 @@ pub fn is_path_in_directory(parent: &Path, path: &Path) -> Result<bool> {
 
 /// Create a file with the content given
 pub fn create_file(path: &Path, content: &str) -> Result<()> {
-    let mut file = File::create(&path).chain_err(|| format!("Failed to create {:?}", path))?;
+    let mut file = File::create(&path)
+        .map_err(|e| Error::chain(format!("Failed to create {:?}", path), e))?;
     file.write_all(content.as_bytes())?;
     Ok(())
 }
@@ -37,7 +38,7 @@ pub fn ensure_directory_exists(path: &Path) -> Result<()> {
 pub fn create_directory(path: &Path) -> Result<()> {
     if !path.exists() {
         create_dir_all(path)
-            .chain_err(|| format!("Was not able to create folder {}", path.display()))?;
+            .map_err(|e| Error::chain(format!("Was not able to create folder {}", path.display()), e))?;
     }
     Ok(())
 }
@@ -46,7 +47,7 @@ pub fn create_directory(path: &Path) -> Result<()> {
 pub fn read_file(path: &Path) -> Result<String> {
     let mut content = String::new();
     File::open(path)
-        .chain_err(|| format!("Failed to open '{:?}'", path.display()))?
+        .map_err(|e| Error::chain(format!("Failed to open '{:?}'", path.display()), e))?
         .read_to_string(&mut content)?;
 
     // Remove utf-8 BOM if any.
@@ -57,6 +58,19 @@ pub fn read_file(path: &Path) -> Result<String> {
     Ok(content)
 }
 
+/// Return the content of a file, with error handling added.
+/// The default error message is overwritten by the message given.
+/// That means it is allocation 2 strings, oh well
+pub fn read_file_with_error(path: &Path, message: &str) -> Result<String> {
+    let res = read_file(&path);
+    if res.is_ok() {
+        return res;
+    }
+    let mut err = Error::msg(message);
+    err.source = res.unwrap_err().source;
+    Err(err)
+}
+
 /// Looks into the current folder for the path and see if there's anything that is not a .md
 /// file. Those will be copied next to the rendered .html file
 pub fn find_related_assets(path: &Path) -> Vec<PathBuf> {

docs/templates/page.html

@@ -4,4 +4,5 @@
 {% block doc_content %}
     <h1>{{page.title}}</h1>
     {{page.content | safe}}
+{{hey}}
 {% endblock doc_content %}

src/cmd/serve.rs

@@ -36,7 +36,7 @@ use ctrlc;
 use notify::{watcher, RecursiveMode, Watcher};
 use ws::{Message, Sender, WebSocket};
 
-use errors::{Result, ResultExt};
+use errors::{Result, Error as ZolaError};
 use site::Site;
 use utils::fs::copy_file;
 
@@ -179,23 +179,23 @@ pub fn serve(
     let mut watcher = watcher(tx, Duration::from_secs(1)).unwrap();
     watcher
         .watch("content/", RecursiveMode::Recursive)
-        .chain_err(|| "Can't watch the `content` folder. Does it exist?")?;
+        .map_err(|e| ZolaError::chain("Can't watch the `content` folder. Does it exist?", e))?;
     watcher
         .watch(config_file, RecursiveMode::Recursive)
-        .chain_err(|| "Can't watch the `config` file. Does it exist?")?;
+        .map_err(|e| ZolaError::chain("Can't watch the `config` file. Does it exist?", e))?;
 
     if Path::new("static").exists() {
         watching_static = true;
         watcher
             .watch("static/", RecursiveMode::Recursive)
-            .chain_err(|| "Can't watch the `static` folder.")?;
+            .map_err(|e| ZolaError::chain("Can't watch the `static` folder.", e))?;
     }
 
     if Path::new("templates").exists() {
         watching_templates = true;
         watcher
             .watch("templates/", RecursiveMode::Recursive)
-            .chain_err(|| "Can't watch the `templates` folder.")?;
+            .map_err(|e| ZolaError::chain("Can't watch the `templates` folder.", e))?;
     }
 
     // Sass support is optional so don't make it an error to no have a sass folder

src/console.rs

@@ -1,4 +1,5 @@
 use std::env;
+use std::error::Error as StdError;
 use std::io::Write;
 use std::time::Instant;
 
@@ -6,7 +7,6 @@ use atty;
 use chrono::Duration;
 use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
 
-use errors::Error;
 use site::Site;
 
 lazy_static! {
@@ -91,13 +91,15 @@ pub fn report_elapsed_time(instant: Instant) {
 }
 
 /// Display an error message and the actual error(s)
-pub fn unravel_errors(message: &str, error: &Error) {
+pub fn unravel_errors(message: &str, error: &StdError) {
     if !message.is_empty() {
         self::error(message);
     }
     self::error(&format!("Error: {}", error));
-    for e in error.iter().skip(1) {
+    let mut cause = error.source();
+    while let Some(e) = cause {
         self::error(&format!("Reason: {}", e));
+        cause = e.source();
     }
 }