Following changed in Perl 5.40:
https://perldoc.perl.org/5.40.0/perldelta#Calling-the-import-method-of-an-unknown-package-produces-a-warning
Which gives following error when starting Fhem under Perl 5.40:
Attempt to call undefined import method with arguments (":all") via package "SetExtensions" (Perhaps you forgot to load the package?) at ./FHEM/10_MQTT_DEVICE.pm line 72, <$fh> line 132.
Since there is no class in SetExtensions.pm, nothing should be imported, just the file included so the functions are available.
Patch:
--- - 2025-10-01 18:51:21.154513839 +0200
+++ /srv/fhem/FHEM/10_MQTT_DEVICE.pm 2025-09-30 18:36:00.000000000 +0200
@@ -68,7 +69,7 @@
use GPUtils qw(:all);
use Net::MQTT::Constants;
-use SetExtensions qw/ :all /;
+use SetExtensions;
BEGIN {
MQTT->import(qw(:all));