The wifi use to work in Ubuntu 18.04, but no longer does. The USB device still works with Windows however. I have been stuck on this problem for over a day now, and it's driving me crazy. I'm a bit of a noob when it comes to Linux, so I might be making a trivial mistake.
I tried to rebuild the dkms
ls /usr/src/linux-headers-* -d | sed -e 's/.*linux-headers-//' | \ sort -V | tac | sudo xargs -n1 /usr/lib/dkms/dkms_autoinstaller start
However, this did not solve the problem. So I decided to start from the ground up and remove the dkms and install new ones.
sudo apt purge rtl8812au-dkms
sudo dkms remove -m rtl8812au -v 4.2.2 --all
Then I checked...
dkms status
To verify everything was empty. It was. Next was to install fresh dkms.
sudo apt install rtl8812au-dkms
Restart, and nothing. However, I gave another dkms status check and sure enough I was getting this error.
rtl8812au, 4.3.8.12175.20140902+dfsg, 4.15.0-38-generic, x86_64: installed (WARNING! Diff between built and installed module!)
Okay time to build them manually after a quick sudo apt purge rtl8812au-dkms. So at first I decided to follow this Q/A. But I was met with the same error. So once again I purged and removed the dkms. And then I tried an older version from a different git.
git clone https://github.com/gnab/rtl8812au.git
sudo cp -r rtl8812au /usr/src/rtl8812au-4.2.2
sudo dkms add -m rtl8812au -v 4.2.2
sudo dkms build -m rtl8812au -v 4.2.2
sudo dkms install -m rtl8812au -v 4.2.2
But still have the same type of error.
rtl8812au, 4.2.2, 4.15.0-38-generic, x86_64: installed (WARNING! Diff between built and installed module!)
I then saw this Q/A where with someone who had a similar problem. Everything looked good, the dkms status read out as...
rtl88x2bu, 5.2.4.4, 4.15.0-38-generic, x86_64: installed
However, after a restart I still couldn't see my wifi device. I've tried dozens of different problem solving techniques at this point, and still have no luck getting it to work. Part of me is considering just getting a PCI wifi card. I'd feel pretty defeated if I had to do this, especially since it WAS working. Any assistance would be greatly appreciated.
Edit1: As requested here is my lsusb readout for the device. It seems to all check out.
Bus 003 Device 002: ID 0bda:8812 Realtek Semiconductor Corp. RTL8812AU 802.11a/b/g/n/ac WLAN Adapter
Edit2: I was able to build the dkms after following this Q/A. I was hoping after the restart the Wifi adapter would work, but it did not :<. In my Additional Drivers tab it shows up too. I've hit so many walls, and I have no idea why it stopped working in the first place. My next thought is to just buy a comparable PCI card.
lsusbWelcome to Ask Ubuntu. – chili555 Oct 28 '18 at 23:52