Bump required python version to 3.6

f-strings are a syntax error with older versions anyway, but let's bump
the version string for any human readers.

diff --git a/mkosi b/mkosi
index 86597d516c2418956d78176a14f7500390d9d050..d0a0e87e6e9e487b84384fc4433fc331a28b0113 100755 (executable)
--- a/mkosi
+++ b/mkosi
@@ -51,8 +51,8 @@ from subprocess import DEVNULL, PIPE
 
 __version__ = '4'
 
-if sys.version_info < (3, 5):
-    sys.exit("Sorry, we need at least Python 3.5.")
+if sys.version_info < (3, 6):
+    sys.exit("Sorry, we need at least Python 3.6.")
 
 # TODO
 # - volatile images