launch: Add warning not to avoid calling launch twice on the same handle.

For more information on this topic, see:
https://www.redhat.com/archives/libguestfs/2012-October/msg00045.html

1 files changed, 6 insertions, 1 deletions

diff --git a/generator/actions.ml b/generator/actions.ml
index 0c1f4ab2..13e54f39 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -197,7 +197,12 @@ Internally libguestfs is implemented by running a virtual machine
 using L<qemu(1)>.
 
 You should call this after configuring the handle
-(eg. adding drives) but before performing any actions." };
+(eg. adding drives) but before performing any actions.
+
+Do not call C<guestfs_launch> twice on the same handle.  Although
+it will not give an error (for historical reasons), the precise
+behaviour when you do this is not well defined.  Handles are
+very cheap to create, so create a new one for each launch." };
 
   { defaults with
     name = "wait_ready";