iotests: Require Python 3.6 or later

Running iotests is not required to build QEMU, so we can have stricter
version requirements for Python here and can make use of new features
and drop compatibility code earlier.

This makes qemu-iotests skip all Python tests if a Python version before
3.6 is used for the build.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 875399d79f7f23253e42f0205859b4274d1f7ba1..588c453a948ec76a471d2a5c5aea1c78db3c2d0a 100755 (executable)
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -633,6 +633,12 @@ then
     export SOCKET_SCM_HELPER="$build_iotests/socket_scm_helper"
 fi
 
+python_usable=false
+if $PYTHON -c 'import sys; sys.exit(0 if sys.version_info >= (3,6) else 1)'
+then
+    python_usable=true
+fi
+
 default_machine=$($QEMU_PROG -machine help | sed -n '/(default)/ s/ .*//p')
 default_alias_machine=$($QEMU_PROG -machine help | \
    sed -n "/(alias of $default_machine)/ { s/ .*//p; q; }")
@@ -809,7 +815,12 @@ do
         start=$(_wallclock)
 
         if [ "$(head -n 1 "$source_iotests/$seq")" == "#!/usr/bin/env python" ]; then
-            run_command="$PYTHON $seq"
+            if $python_usable; then
+                run_command="$PYTHON $seq"
+            else
+                run_command="false"
+                echo "Unsupported Python version" > $seq.notrun
+            fi
         else
             run_command="./$seq"
         fi