Change: flush progress output after every write

2 files changed, 11 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index f9766ce..e17d765 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,15 @@
 NEWS for vmdb2, the Debian disk image builder
 =============================================================================
 
+Version 0.15+git, not yet released
+------------------------------------
+
+* Progress output is now flushed after every write. This matters, when
+  the output goes to a pipe, because then Python would buffer the
+  output, meaning that progress output gets delayed until the buffer
+  fills up, and that's useless.
+
+
 Version 0.15, released 2020-05-05
 ------------------------------------
 
diff --git a/vmdb/runcmd.py b/vmdb/runcmd.py
index ae4a6d0..7cd6406 100644
--- a/vmdb/runcmd.py
+++ b/vmdb/runcmd.py
@@ -35,12 +35,14 @@ def set_verbose_progress(verbose):
 def error(msg):
     logging.error(msg, exc_info=True)
     sys.stderr.write('ERROR: {}\n'.format(msg))
+    sys.stderr.flush()
 
 
 def progress(msg):
     logging.info(msg)
     if _verbose:
         sys.stdout.write('{}\n'.format(msg))
+        sys.stdout.flush()
 
 
 def runcmd(argv, **kwargs):