Much more user-friendly error messages when bup can't exec the server.

...which happens unfortunately often, including in 'make test' when PATH
doesn't include bup.  I'll fix that next.  But it makes sense to fix the
error messages first :)

diff --git a/client.py b/client.py
index 3902066645ea60fc7db098d14b11607c0232caf5..a83894dc4df1033457143960916ecccfc74c53b6 100644 (file)
--- a/client.py
+++ b/client.py
@@ -1,4 +1,4 @@
-import re, struct
+import re, struct, errno
 import git
 from helpers import *
 from subprocess import Popen, PIPE
@@ -10,6 +10,8 @@ class Client:
     def __init__(self, remote, create=False):
         self._busy = None
         self._indexes_synced = 0
+        self.p = None
+        self.conn = None
         rs = remote.split(':', 1)
         if len(rs) == 1:
             (host, dir) = ('NONE', remote)
@@ -21,7 +23,10 @@ class Client:
         self.cachedir = git.repo('index-cache/%s'
                                  % re.sub(r'[^@:\w]', '_', 
                                           "%s:%s" % (host, dir)))
-        self.p = p = Popen(argv, stdin=PIPE, stdout=PIPE)
+        try:
+            self.p = p = Popen(argv, stdin=PIPE, stdout=PIPE)
+        except OSError, e:
+            raise ClientError, 'exec %r: %s' % (argv[0], e), sys.exc_info()[2]
         self.conn = conn = Conn(p.stdout, p.stdin)
         if dir:
             dir = re.sub(r'[\r\n]', ' ', dir)
@@ -29,10 +34,16 @@ class Client:
                 conn.write('init-dir %s\n' % dir)
             else:
                 conn.write('set-dir %s\n' % dir)
-            conn.check_ok()
+            self.check_ok()
 
     def __del__(self):
-        self.close()
+        try:
+            self.close()
+        except IOError, e:
+            if e.errno == errno.EPIPE:
+                pass
+            else:
+                raise
 
     def close(self):
         if self.conn and not self._busy:
@@ -49,6 +60,15 @@ class Client:
         self.conn = None
         self.p = None
 
+    def check_ok(self):
+        rv = self.p.poll()
+        if rv != None:
+            raise ClientError('server exited unexpectedly with code %r' % rv)
+        try:
+            self.conn.check_ok()
+        except Exception, e:
+            raise ClientError, e, sys.exc_info()[2]
+
     def check_busy(self):
         if self._busy:
             raise ClientError('already busy with command %r' % self._busy)
@@ -71,7 +91,7 @@ class Client:
             assert(line.find('/') < 0)
             if not os.path.exists(os.path.join(self.cachedir, line)):
                 needed[line] = 1
-        conn.check_ok()
+        self.check_ok()
 
         for f in os.listdir(self.cachedir):
             if f.endswith('.idx') and not f in all:
@@ -90,7 +110,7 @@ class Client:
             f = open(fn + '.tmp', 'w')
             for b in chunkyreader(conn, n):
                 f.write(b)
-            conn.check_ok()
+            self.check_ok()
             f.close()
             os.rename(fn + '.tmp', fn)
 
@@ -114,7 +134,7 @@ class Client:
         self.check_busy()
         self.conn.write('read-ref %s\n' % refname)
         r = self.conn.readline().strip()
-        self.conn.check_ok()
+        self.check_ok()
         if r:
             assert(len(r) == 40)   # hexified sha
             return r.decode('hex')
@@ -126,7 +146,7 @@ class Client:
         self.conn.write('update-ref %s\n%s\n%s\n' 
                         % (refname, newval.encode('hex'),
                            (oldval or '').encode('hex')))
-        self.conn.check_ok()
+        self.check_ok()
 
     def cat(self, id):
         self.check_busy()
@@ -136,7 +156,7 @@ class Client:
             sz = struct.unpack('!I', self.conn.read(4))[0]
             if not sz: break
             yield self.conn.read(sz)
-        self.conn.check_ok()
+        self.check_ok()
         self._not_busy()
 
 

diff --git a/helpers.py b/helpers.py
index f4403ef0ce9c9b92d92eea7c2ec5297818821c37..b478d61653cde002fdd9c865adbf5fa2af451b7d 100644 (file)
--- a/helpers.py
+++ b/helpers.py
@@ -82,13 +82,13 @@ class Conn:
         rl = ''
         for rl in linereader(self.inp):
             #log('%d got line: %r\n' % (os.getpid(), rl))
-            if not rl:
+            if not rl:  # empty line
                 continue
             elif rl == 'ok':
                 return True
             else:
-                break
-        raise Exception('expected "ok", got %r' % rl)
+                raise Exception('expected "ok", got %r' % rl)
+        raise Exception('server exited unexpectedly; see errors above')
 
 
 def linereader(f):