issue:
  File "/home/xtf/xtf-runner", line 410, in interpret_selection
    if not line.startswith("xen_caps"):
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: startswith first arg must be bytes or a tuple of bytes, not str

Adding `universal_newlines` open stdout as text file, so line should
be a `str`. `universal_newlines` is available on python 2.7. A new
alias `text` is only available in python 3.7.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---

Notes:
    I've only tested the patch on Debian Bookworm, with python-is-python3
    package (python symlink) as osstest run `./xtf-runner ...`.
    
    I haven't tried python2.7.

 xtf-runner | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xtf-runner b/xtf-runner
index 6352a5b..5741e64 100755
--- a/xtf-runner
+++ b/xtf-runner
@@ -403,7 +403,7 @@ def interpret_selection(opts):
 
         host_envs = []
 
-        cmd = Popen(['xl', 'info'], stdout = PIPE)
+        cmd = Popen(['xl', 'info'], stdout = PIPE, universal_newlines=True)
         stdout, _ = cmd.communicate()
 
         for line in stdout.splitlines():
-- 
Anthony PERARD