diff --git a/mercurial/bookmarks.py b/mercurial/bookmarks.py
--- a/mercurial/bookmarks.py
+++ b/mercurial/bookmarks.py
@@ -29,7 +29,7 @@ def read(repo):
             sha, refspec = line.strip().split(' ', 1)
             refspec = encoding.tolocal(refspec)
             bookmarks[refspec] = repo.changelog.lookup(sha)
-    except:
+    except IOError:
         pass
     return bookmarks
 
diff --git a/mercurial/bundlerepo.py b/mercurial/bundlerepo.py
--- a/mercurial/bundlerepo.py
+++ b/mercurial/bundlerepo.py
@@ -294,7 +294,7 @@ def getremotechanges(ui, repo, other, re
     if not incoming:
         try:
             os.unlink(bundlename)
-        except:
+        except OSError:
             pass
         return other, None, None, None
 
diff --git a/mercurial/changelog.py b/mercurial/changelog.py
--- a/mercurial/changelog.py
+++ b/mercurial/changelog.py
@@ -185,7 +185,7 @@ class changelog(revlog.revlog):
             try:
                 # various tools did silly things with the time zone field.
                 timezone = int(extra_data[0])
-            except:
+            except ValueError:
                 timezone = 0
             extra = {}
         else:
diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -293,7 +293,7 @@ def addremove(repo, pats=[], opts={}, dr
         good = True
         try:
             audit_path(abs)
-        except:
+        except (OSError, util.Abort):
             good = False
         rel = m.rel(abs)
         exact = m.exact(abs)
diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -805,7 +805,7 @@ class workingctx(changectx):
                 p = self._repo.wjoin(f)
                 try:
                     st = os.lstat(p)
-                except:
+                except OSError:
                     ui.warn(_("%s does not exist!\n") % join(f))
                     rejected.append(f)
                     continue
diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -133,7 +133,7 @@ def _runcatch(ui, args):
         elif hasattr(inst, "reason"):
             try: # usually it is in the form (errno, strerror)
                 reason = inst.reason.args[1]
-            except: # it might be anything, for example a string
+            except AttributeError: # it might be anything, for example a string
                 reason = inst.reason
             ui.warn(_("abort: error: %s\n") % reason)
         elif hasattr(inst, "args") and inst.args[0] == errno.EPIPE:
diff --git a/mercurial/hg.py b/mercurial/hg.py
--- a/mercurial/hg.py
+++ b/mercurial/hg.py
@@ -363,7 +363,7 @@ def clone(ui, source, dest=None, pull=Fa
                 try:
                     m = dest_repo.lookup(n)
                     dest_repo._bookmarks[k] = m
-                except:
+                except error.RepoLookupError:
                     pass
             if rb:
                 bookmarks.write(dest_repo)
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -549,7 +549,7 @@ class localrepository(repo.repository):
         try:
             if len(key) == 20:
                 key = hex(key)
-        except:
+        except TypeError:
             pass
         raise error.RepoLookupError(_("unknown revision '%s'") % key)
 
diff --git a/mercurial/posix.py b/mercurial/posix.py
--- a/mercurial/posix.py
+++ b/mercurial/posix.py
@@ -59,7 +59,7 @@ def set_flags(f, l, x):
             os.unlink(f)
             try:
                 os.symlink(data, f)
-            except:
+            except OSError:
                 # failed to make a link, rewrite file
                 fp = open(f, "w")
                 fp.write(data)
diff --git a/mercurial/sshrepo.py b/mercurial/sshrepo.py
--- a/mercurial/sshrepo.py
+++ b/mercurial/sshrepo.py
@@ -167,7 +167,7 @@ class sshrepository(wireproto.wirereposi
         self.readerr()
         try:
             l = int(l)
-        except:
+        except ValueError:
             self._abort(error.ResponseError(_("unexpected response:"), l))
         return self.pipei.read(l)
 
@@ -208,7 +208,7 @@ class sshrepository(wireproto.wirereposi
             return 1
         try:
             return int(r)
-        except:
+        except ValueError:
             self._abort(error.ResponseError(_("unexpected response:"), r))
 
 instance = sshrepository
diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -206,12 +206,12 @@ def tempfilter(s, cmd):
         try:
             if inname:
                 os.unlink(inname)
-        except:
+        except OSError:
             pass
         try:
             if outname:
                 os.unlink(outname)
-        except:
+        except OSError:
             pass
 
 filtertable = {
@@ -407,7 +407,7 @@ def copyfile(src, dest):
     if os.path.islink(src):
         try:
             os.unlink(dest)
-        except:
+        except OSError:
             pass
         os.symlink(os.readlink(src), dest)
     else:
@@ -556,7 +556,7 @@ def checkcase(path):
         if s2 == s1:
             return False
         return True
-    except:
+    except OSError:
         return True
 
 _fspathcache = {}
diff --git a/mercurial/windows.py b/mercurial/windows.py
--- a/mercurial/windows.py
+++ b/mercurial/windows.py
@@ -32,7 +32,8 @@ class winstdout(object):
     def close(self):
         try:
             self.fp.close()
-        except: pass
+        except IOError:
+            pass
 
     def write(self, s):
         try:
@@ -243,7 +244,7 @@ def _removedirs(name):
             if osutil.listdir(head):
                 return
             os.rmdir(head)
-        except:
+        except (ValueError, OSError):
             break
         head, tail = os.path.split(head)