diff --git a/lib/bb/build.py b/lib/bb/build.py
index 95f1dcf..da4c911 100644
--- a/lib/bb/build.py
+++ b/lib/bb/build.py
@@ -135,7 +135,8 @@ class LogTee(object):
 
     def __repr__(self):
         return '<LogTee {0}>'.format(self.name)
-
+    def flush(self):
+        self.outfile.flush()
 
 def exec_func(func, d, dirs = None):
     """Execute an BB 'function'"""
diff --git a/lib/bb/process.py b/lib/bb/process.py
index b74cb18..9848fc3 100644
--- a/lib/bb/process.py
+++ b/lib/bb/process.py
@@ -1,6 +1,9 @@
 import logging
 import signal
 import subprocess
+import fcntl
+import errno
+import select
 
 logger = logging.getLogger('BitBake.Process')
 
@@ -70,18 +73,40 @@ def _logged_communicate(pipe, log, input):
 
     bufsize = 512
     outdata, errdata = [], []
+    rin = []
+
+    if pipe.stdout is not None:
+        fd = pipe.stdout.fileno()
+        fl = fcntl.fcntl(fd, fcntl.F_GETFL)
+        fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
+        rin.append(pipe.stdout)
+    if pipe.stderr is not None:
+        fd = pipe.stderr.fileno()
+        fl = fcntl.fcntl(fd, fcntl.F_GETFL)
+        fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
+        rin.append(pipe.stderr)
+
     while pipe.poll() is None:
-        if pipe.stdout is not None:
+        rlist = rin
+        try:
+            r,w,e = select.select (rlist, [], [])
+        except OSError, e:
+            if e.errno != errno.EINTR:
+                raise
+
+        if pipe.stdout in r:
             data = pipe.stdout.read(bufsize)
             if data is not None:
                 outdata.append(data)
                 log.write(data)
+                log.flush()
 
-        if pipe.stderr is not None:
+        if pipe.stderr in r:
             data = pipe.stderr.read(bufsize)
             if data is not None:
                 errdata.append(data)
                 log.write(data)
+                log.flush()
     return ''.join(outdata), ''.join(errdata)
 
 def run(cmd, input=None, log=None, **options):