Narrow bare except blocks so real errors aren't swallowed (roadmap A4)

Replaced all 46 bare 'except:' across the package with specific exception
types, and logged the cases that indicate a real problem:

- config load/save: FileNotFoundError is the silent first-run case; other
  OSError/ValueError/UnicodeDecodeError are logged.
- ffprobe/avprobe: JSON parse failures are now logged (previously a media
  file that ffprobe couldn't read just silently failed to import); decode
  fallbacks -> UnicodeDecodeError; duration parse -> ValueError/TypeError/
  KeyError; install check -> OSError/SubprocessError.
- executor: pre_/post_function and progress-polling hooks now use hasattr
  checks, and a real exception inside a defined hook is logged instead of
  swallowed; decode fallbacks and numeric parses narrowed.
- best-effort filesystem ops (makedirs/unlink) -> OSError.
- all backend check_is_installed probes -> OSError/SubprocessError.
- shutdown: also fixes a latent NameError ('failure' was only set in the
  except branch, so a successful logind PowerOff would crash the handler).

No bare 'except:' remain. Full suite (51 tests) green; GUI starts clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/devedeng/avbase.py

@@ -30,7 +30,7 @@ class avbase(devedeng.executor.executor):
             (stdout, stderr) = handle.communicate()
             if 0 != handle.wait():
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
         self.check_version_txt(stdout)
 
@@ -54,7 +54,7 @@ class avbase(devedeng.executor.executor):
                     else:
                         major = int(line[15:pos1].strip())
                         minor = int(line[pos1 + 1:pos2].strip())
-                except:
+                except (ValueError, IndexError):
                     return False
                 self.major_version = major
                 self.minor_version = minor

src/devedeng/avconv.py

@@ -103,7 +103,7 @@ class avconv(devedeng.avbase.avbase):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):
@@ -648,7 +648,7 @@ class avconv(devedeng.avbase.avbase):
                 for e in parts:
                     try:
                         v = float(e)
-                    except:
+                    except ValueError:
                         continue
                     t = t * 60.0 + v
                 t /= self.final_length

src/devedeng/avprobe.py

@@ -43,7 +43,7 @@ class avprobe(devedeng.avbase.avbase):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):
@@ -70,7 +70,7 @@ class avprobe(devedeng.avbase.avbase):
 
         try:
             stdout2 = stdout.decode("utf-8")
-        except:
+        except UnicodeDecodeError:
             stdout2 = stdout.decode("latin1")
         self.config.append_static_log("AVProbe JSON data: " + str(stdout2))
         return self.process_json(stdout2, file_name)
@@ -97,7 +97,9 @@ class avprobe(devedeng.avbase.avbase):
             "Getting data for {:s} with avprobe".format(file_name))
         try:
             video_data = json.loads(stdout2)
-        except:
+        except ValueError as e:
+            self.config.append_static_log(
+                "avprobe returned unparseable JSON for %s: %s" % (file_name, e))
             return True  # There was an error reading the JSON data
 
         if not("streams" in video_data):
@@ -108,7 +110,7 @@ class avprobe(devedeng.avbase.avbase):
             if (self.original_length == -1) and ("duration" in element):
                 try:
                     self.original_length = int(float(element["duration"]))
-                except:
+                except (ValueError, TypeError, KeyError):
                     self.original_length = -1
 
             if (element["codec_type"] == "video"):
@@ -173,7 +175,7 @@ class avprobe(devedeng.avbase.avbase):
             try:
                 stdout2 = stdout.decode("utf-8") + \
                     "\n" + stderr.decode("utf-8")
-            except:
+            except UnicodeDecodeError:
                 stdout2 = stdout.decode("latin1") + \
                     "\n" + stderr.decode("latin1")
             self.config.append_static_log(

src/devedeng/brasero.py

@@ -39,7 +39,7 @@ class brasero(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):

src/devedeng/choose_disc_type.py

@@ -103,7 +103,7 @@ class choose_disc_type(GObject.GObject):
             (stdout, stderr) = handle.communicate()
             retval = handle.wait()
             return True
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def set_type(self, disc_type):

src/devedeng/configuration_data.py

@@ -210,8 +210,11 @@ class configuration(GObject.GObject):
                         pass
                     continue
             config_data.close()
-        except:
+        except FileNotFoundError:
-            pass
+            pass  # no config file yet (first run) — defaults are used
+        except (OSError, ValueError, UnicodeDecodeError) as e:
+            self.append_static_log(
+                "Error reading config file %s: %s" % (config_path, e))
 
         return False
 
@@ -285,8 +288,8 @@ class configuration(GObject.GObject):
             config_path = os.path.join(os.environ.get("HOME"), ".devedeng")
             if os.path.exists(config_path):
                 os.remove(config_path)
-        except:
+        except OSError as e:
-            pass
+            self.append_static_log("Error writing config file: %s" % e)
 
     def append_log(self, data, cr=True):
 

src/devedeng/dvd_menu.py

@@ -201,7 +201,7 @@ class dvd_menu(devedeng.interface_manager.interface_manager):
 
         try:
             fontsize = float(font_elements[-1])
-        except:
+        except (ValueError, IndexError):
             fontsize = 12
 
         return fontname, fontstyle, fontslant, fontsize
@@ -635,7 +635,7 @@ class dvd_menu(devedeng.interface_manager.interface_manager):
         menu_folder = os.path.join(base_path, "menu")
         try:
             os.makedirs(menu_folder)
-        except:
+        except OSError:
             pass
         n_page = 0
         self.pages = 1

src/devedeng/dvdauthor_converter.py

@@ -33,7 +33,7 @@ class dvdauthor_converter(devedeng.executor.executor):
         movie_path = os.path.join(path, "dvd_tree")
         try:
             os.makedirs(movie_path)
-        except:
+        except OSError:
             pass
 
         xml_file = self.create_dvdauthor_xml(path, file_movies, menu_entries, start_with_menu, play_all_opt, menuWide, segment_lengths)
@@ -73,7 +73,7 @@ class dvdauthor_converter(devedeng.executor.executor):
         datapath = os.path.join(movie_folder, "dvd_tree")
         try:
             os.makedirs(xmlpath)
-        except:
+        except OSError:
             pass
 
         if (len(file_movies) == 1) and (menu_entries is None):

src/devedeng/executor.py

@@ -120,20 +120,20 @@ class executor(GObject.GObject):
         self.progress_bar[0].set_label(self.text)
         self.progress_bar[1].set_fraction(0.0)
         self.progress_bar[0].show_all()
-        # call, if it exists, the pre-function
+        # call the pre-function if this process defines one
-        try:
+        if hasattr(self, "pre_function"):
-            self.pre_function()
+            try:
-        except:
+                self.pre_function()
-            pass
+            except Exception as e:
+                self.config.append_static_log(
+                    "pre_function failed for %s: %s" % (self.text, e))
         self.launch_process(self.command_var)
         if self.use_pulse_mode != self.pulse_mode:
             self.set_pulse_mode(self.use_pulse_mode)
         # let subclasses start any timer-based progress polling (e.g. ffmpeg
         # reads its -progress file on a GLib timer). No-op by default.
-        try:
+        if hasattr(self, "start_progress_polling"):
             self.start_progress_polling()
-        except AttributeError:
-            pass
 
     def remove_ansi(self, line):
 
@@ -189,11 +189,11 @@ class executor(GObject.GObject):
             self.config.append_log(self.launch_command)
             try:
                 self.config.append_log(stdout_r.decode("utf-8"))
-            except:
+            except UnicodeDecodeError:
                 self.config.append_log(stdout_r.decode("latin-1"))
             try:
                 self.config.append_log(stderr_r.decode("utf-8"))
-            except:
+            except UnicodeDecodeError:
                 self.config.append_log(stderr_r.decode("latin-1"))
             return (stdout_r, stderr_r)
 
@@ -396,16 +396,16 @@ class executor(GObject.GObject):
 
         self.set_pulse_mode(False)
         # stop any subclass progress polling timer
-        try:
+        if hasattr(self, "stop_progress_polling"):
             self.stop_progress_polling()
-        except AttributeError:
-            pass
 
-        # call, if it exists, the post-function
+        # call the post-function if this process defines one
-        try:
+        if hasattr(self, "post_function"):
-            self.post_function(retval, self.killed)
+            try:
-        except:
+                self.post_function(retval, self.killed)
-            pass
+            except Exception as e:
+                self.config.append_static_log(
+                    "post_function failed for %s: %s" % (self.text, e))
 
         if self.killed:
             retval = 0
@@ -435,13 +435,13 @@ class executor(GObject.GObject):
         if (pos == -1):
             try:
                 return float(data)
-            except:
+            except (ValueError, TypeError):
                 return 0
         else:
             try:
                 data1 = float(data[:pos])
                 data2 = float(data[pos + 1:])
-            except:
+            except (ValueError, TypeError):
                 return 0
             if (data2 == 0):
                 return 0

src/devedeng/ffmpeg.py

@@ -106,7 +106,7 @@ class ffmpeg(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):
@@ -124,7 +124,7 @@ class ffmpeg(devedeng.executor.executor):
                     if line.startswith("ffmpeg version "):
                         version_number = int(re.search(r"[0-9]+", line).group())
                         break
-        except:
+        except (OSError, subprocess.SubprocessError, ValueError, AttributeError):
             version_number = 7
             pass
         print(f"Detected ffmpeg version number: {version_number}")
@@ -829,7 +829,7 @@ class ffmpeg(devedeng.executor.executor):
                 for e in parts:
                     try:
                         v = float(e)
-                    except:
+                    except ValueError:
                         continue
                     t = t * 60.0 + v
                 t /= self.final_length

src/devedeng/ffprobe.py

@@ -43,7 +43,7 @@ class ffprobe(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):
@@ -69,7 +69,7 @@ class ffprobe(devedeng.executor.executor):
         (stdout, stderr) = self.launch_process(command_line, False)
         try:
             stdout2 = stdout.decode("utf-8")
-        except:
+        except UnicodeDecodeError:
             stdout2 = stdout.decode("latin1")
         self.config.append_static_log("FFProbe JSON data: " + str(stdout2))
         return self.process_json(file_name, stdout2)
@@ -97,7 +97,9 @@ class ffprobe(devedeng.executor.executor):
             "Getting data for {:s} with ffprobe".format(file_name))
         try:
             video_data = json.loads(stdout2)
-        except:
+        except ValueError as e:
+            self.config.append_static_log(
+                "ffprobe returned unparseable JSON for %s: %s" % (file_name, e))
             return True  # There was an error reading the JSON data
 
         if not("streams" in video_data):
@@ -108,7 +110,7 @@ class ffprobe(devedeng.executor.executor):
             if (self.original_length == -1) and ("duration" in element):
                 try:
                     self.original_length = int(float(element["duration"]))
-                except:
+                except (ValueError, TypeError, KeyError):
                     self.original_length = -1
 
             if (element["codec_type"] == "video"):
@@ -176,7 +178,7 @@ class ffprobe(devedeng.executor.executor):
             try:
                 stdout2 = stdout.decode("utf-8") + \
                     "\n" + stderr.decode("utf-8")
-            except:
+            except UnicodeDecodeError:
                 stdout2 = stdout.decode("latin1") + \
                     "\n" + stderr.decode("latin1")
             self.config.append_static_log("Using ffprobe human readable format: " + str(stdout2))

src/devedeng/file_copy.py

@@ -47,7 +47,7 @@ class file_copy(devedeng.executor.executor):
 
         try:
             copied = float(parts[0])
-        except:
+        except (ValueError, IndexError):
             return
 
         p = copied / self.file_size

src/devedeng/genisoimage.py

@@ -42,7 +42,7 @@ class genisoimage(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):

src/devedeng/k3b.py

@@ -39,7 +39,7 @@ class k3b(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):

src/devedeng/mkisofs.py

@@ -42,7 +42,7 @@ class mkisofs(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):

src/devedeng/mplayer.py

@@ -42,7 +42,7 @@ class mplayer(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):

src/devedeng/mpv.py

@@ -41,7 +41,7 @@ class mpv(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):

src/devedeng/project.py

@@ -908,16 +908,16 @@ class devede_project:
                 if self.config.disc_type == "dvd":
                     try:
                         os.unlink(os.path.join(data.path, data.name + ".iso"))
-                    except:
+                    except OSError:
                         pass
                 if (self.config.disc_type == "vcd") or (self.config.disc_type == "svcd") or (self.config.disc_type == "cvd"):
                     try:
                         os.unlink(os.path.join(data.path, data.name + ".bin"))
-                    except:
+                    except OSError:
                         pass
                     try:
                         os.unlink(os.path.join(data.path, data.name + ".cue"))
-                    except:
+                    except OSError:
                         pass
             else:
                 return
@@ -968,7 +968,7 @@ class devede_project:
         movie_folder = os.path.join(data.path, "movies")
         try:
             os.makedirs(movie_folder)
-        except:
+        except OSError:
             pass
         counter = 0
         if self.disc_type == "divx":

src/devedeng/shutdown.py

@@ -22,11 +22,12 @@ class shutdown:
     def __init__(self):
 
         # First, try with logind
+        failure = False
         try:
             bus = Gio.bus_get_sync(Gio.BusType.SYSTEM, None)
             bus.call_sync("org.freedesktop.login1", "/org/freedesktop/login1", "org.freedesktop.login1.Manager",
                           "PowerOff", GLib.Variant_boolean('(bb)', (False, False)), None, Gio.DBusCallFlags.NONE, -1, None)
-        except:
+        except Exception:
             failure = True
 
         if (failure):
@@ -37,7 +38,7 @@ class shutdown:
                 bus = Gio.bus_get_sync(Gio.BusType.SYSTEM, None)
                 bus.call_sync("org.freedesktop.ConsoleKit", "/org/freedesktop/ConsoleKit/Manager", "org.freedesktop.ConsoleKit.Manager",
                               "Stop", None, None, Gio.DBusCallFlags.NONE, -1, None)
-            except:
+            except Exception:
                 failure = True
 
         if (failure):
@@ -48,5 +49,5 @@ class shutdown:
                 bus = Gio.bus_get_sync(Gio.BusType.SYSTEM, None)
                 bus.call_sync("org.freedesktop.Hal", "/org/freedesktop/Hal/devices/computer", "org.freedesktop.Hal.Device.SystemPowerManagement",
                               "Shutdown", None, None, Gio.DBusCallFlags.NONE, -1, None)
-            except:
+            except Exception:
                 failure = True

src/devedeng/vlc.py

@@ -39,7 +39,7 @@ class vlc(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):

src/devedeng/xfburn.py

@@ -38,7 +38,7 @@ class xfburn(devedeng.executor.executor):
                 return True
             else:
                 return False
-        except:
+        except (OSError, subprocess.SubprocessError):
             return False
 
     def __init__(self):