"internal error: reply callback called twice"
This bug is rare but well-understood. Unfortunately it's also
quite hard to fix cleanly.
+
+[libguestfs] write-file does not support strings containing ASCII NUL.
+
+[perl] Perl bindings cause a segfault when you call any command which
+takes a StringList (eg. $g->command).
+[should be fixed now]
+
+[libguestfs] OptString parameters in the bindings are often not
+handled correctly. For example in OCaml (but this is NOT exclusive
+to OCaml), OptString should become 'string option'.
+
+[libguestfs] Certain functions such as 'set-path' can take NULL
+parameters, but the parameters are not OptString.