From 1da076773d523f6cd0cd8f233e6f8ae73a693391 Mon Sep 17 00:00:00 2001
From: Oliverpool <oliverpool@hotmail.fr>
Date: Mon, 9 Nov 2015 07:30:11 +0100
Subject: [PATCH 1/4] Test for lilypond compiler before starting compilation

---
 patacrep/build.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/patacrep/build.py b/patacrep/build.py
index a720b9b1..f3391744 100644
--- a/patacrep/build.py
+++ b/patacrep/build.py
@@ -123,6 +123,9 @@ class Songbook(object):
 
         renderer.render_tex(output, config)
 
+    def requires_lilypond(self):
+        return 'lilypond' in self.config.get('bookoptions', [])
+
 def _log_pipe(pipe):
     """Log content from `pipe`."""
     while 1:
@@ -227,6 +230,20 @@ class SongbookBuilder(object):
         except Exception as error:
             raise errors.ExecutableNotFound(compiler)
 
+        # Test if lilypond compiler is accessible
+        lilypond_compiler = 'lilypond'
+        if self.songbook.requires_lilypond():
+            try:
+                check_call(
+                    [lilypond_compiler, "--version"],
+                    stdin=PIPE,
+                    stdout=PIPE,
+                    stderr=PIPE,
+                    universal_newlines=True,
+                    )
+            except Exception as error:
+                raise errors.ExecutableNotFound(lilypond_compiler)
+
         # Perform compilation
         try:
             process = Popen(

From 95d27724ea2522ae7a3ef6eed4df90e082af7882 Mon Sep 17 00:00:00 2001
From: Oliverpool <oliverpool@hotmail.fr>
Date: Mon, 9 Nov 2015 07:33:26 +0100
Subject: [PATCH 2/4] (pylint) Add docstring

---
 patacrep/build.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/patacrep/build.py b/patacrep/build.py
index f3391744..83817d1c 100644
--- a/patacrep/build.py
+++ b/patacrep/build.py
@@ -124,6 +124,7 @@ class Songbook(object):
         renderer.render_tex(output, config)
 
     def requires_lilypond(self):
+        """Tell if lilypond is part of the bookoptions"""
         return 'lilypond' in self.config.get('bookoptions', [])
 
 def _log_pipe(pipe):

From 61bc9a5731e9b459e8aaf3dbf1f446f13b6331a7 Mon Sep 17 00:00:00 2001
From: Oliverpool <oliverpool@hotmail.fr>
Date: Mon, 9 Nov 2015 07:41:18 +0100
Subject: [PATCH 3/4] move variable declaration

---
 patacrep/build.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/patacrep/build.py b/patacrep/build.py
index 83817d1c..baa335fb 100644
--- a/patacrep/build.py
+++ b/patacrep/build.py
@@ -232,8 +232,8 @@ class SongbookBuilder(object):
             raise errors.ExecutableNotFound(compiler)
 
         # Test if lilypond compiler is accessible
-        lilypond_compiler = 'lilypond'
         if self.songbook.requires_lilypond():
+            lilypond_compiler = 'lilypond'
             try:
                 check_call(
                     [lilypond_compiler, "--version"],

From 0ebf52a9c9ac68a4a4d4f4b1ed5a41d2e363eff3 Mon Sep 17 00:00:00 2001
From: Louis <spalax@gresille.org>
Date: Sat, 21 Nov 2015 02:12:50 +0100
Subject: [PATCH 4/4] More precise exception handling

---
 patacrep/build.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/patacrep/build.py b/patacrep/build.py
index baa335fb..f61a5dae 100644
--- a/patacrep/build.py
+++ b/patacrep/build.py
@@ -228,7 +228,7 @@ class SongbookBuilder(object):
                 stderr=PIPE,
                 universal_newlines=True,
                 )
-        except Exception as error:
+        except FileNotFoundError as error:
             raise errors.ExecutableNotFound(compiler)
 
         # Test if lilypond compiler is accessible
@@ -242,7 +242,7 @@ class SongbookBuilder(object):
                     stderr=PIPE,
                     universal_newlines=True,
                     )
-            except Exception as error:
+            except FileNotFoundError as error:
                 raise errors.ExecutableNotFound(lilypond_compiler)
 
         # Perform compilation