Improve error msg for ebook generation

1 files changed, 9 insertions, 2 deletions

diff --git a/lib/output/ebook.js b/lib/output/ebook.js
index 0cd1807..a74af41 100644
--- a/lib/output/ebook.js
+++ b/lib/output/ebook.js
@@ -5,6 +5,7 @@ var juice = require('juice');
 var command = require('../utils/command');
 var fs = require('../utils/fs');
 var Promise = require('../utils/promise');
+var error = require('../utils/error');
 var WebsiteOutput = require('./website');
 var assetsInliner = require('./assets-inliner');
 
@@ -59,12 +60,18 @@ EbookOutput.prototype.finish = function() {
         ].join(' ');
 
         return command.exec(cmd)
+        .progress(function(data) {
+            that.book.log.debug(data);
+        })
         .fail(function(err) {
             if (err.code == 127) {
-                err = new Error('Need to install ebook-convert from Calibre');
+                throw error.RequireInstallError({
+                    cmd: 'ebook-convert',
+                    install: 'Install it from Calibre: https://calibre-ebook.com'
+                });
             }
 
-            throw err;
+            throw error.EbookError(err);
         });
     });
 };