Similar to 79f24568e5e70, this fixes the following warnings:

           CHK version_gen.h
           LEX convert-dtsv0-lexer.lex.c
  make[1]: flex: Command not found
           BISON dtc-parser.tab.c
  make[1]: bison: Command not found
           LEX dtc-lexer.lex.c
  make[1]: flex: Command not found

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 tests/vm/ubuntu.i386 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/vm/ubuntu.i386 b/tests/vm/ubuntu.i386
index be16ceed50..88b661b6d8 100755
--- a/tests/vm/ubuntu.i386
+++ b/tests/vm/ubuntu.i386
@@ -81,7 +81,7 @@ class UbuntuX86VM(basevm.BaseVM):
         # The previous update sometimes doesn't survive a reboot, so do it again
         self.ssh_root_check("apt-get update")
         self.ssh_root_check("apt-get build-dep -y qemu")
-        self.ssh_root_check("apt-get install -y libfdt-dev")
+        self.ssh_root_check("apt-get install -y libfdt-dev flex bison")
         self.ssh_root("poweroff")
         self.wait()
         if os.path.exists(img):
-- 
2.18.0