Dummy network device in Ubuntu Linux 18.04

Ubuntu is moving away from the old /etc/network/interfaces or /etc/network/interfaces.d/*.cfg style of configuration towards netplan. Unfortunately nobody seems to have thought about dummy network interface support. There seems to be a workaround with a bridge device without attached interfaces, but I could not get netplan to assign IP addresses to that bridge interface and it furthermore leads to the boot-up process hanging for a few minutes.

I therefore stick with the old /etc/network/interfaces for now and work around a bug with the dummy module initialization in 18.04 like this:

auto dummy0
iface dummy0 inet static
address 10.0.0.1
netmask 255.255.255.0
pre-up rmmod dummy; modprobe dummy numdummies=4

The last line did the trick.

Reducing CPU load and energy consumption of TeXstudio on the Mac

TeXstudio is a decent and free TeX editor on the Mac. One aspect of it bothered me, though: It uses too much CPU for no obvious reason. Even when no tex documents are open, it (version 2.10.8) does *something* very CPU intensive every ~8 seconds. On a desktop computer this wouldn’t be much of a hassle, but on a laptop unnecessary mean wasted energy and less battery life. With TeXstudio on a MacBook Pro it actually means several hours less battery life.

Using the Activity Monitor I found TeXstudio to frequently scan for network interfaces and nearby Wifi networks. That is very odd for a TeX editor and I cannot think of a good reason for it to do so.

TeXstudio is scanning for WIFI networks

TeXstudio is scanning for WIFI networks

Apparently, libqcorewlanbearer.dylib is involved. Simple fix: Delete it.

$ rm /Applications/texstudio.app/Contents/PlugIns/bearer/libqcorewlanbearer.dylib

TeXstudio will continue to work just fine but will use way less energy doing so. Why does this matter? Because it is spring and I want to work outside. 😀