Please read this: [HowTo] Provide System Information
and press the three dots … below your post and press the to give us more information so we can see what’s really going on.
Now we know the symptom of the disease, but we need some more probing to know where the origin lies…
An inxi --admin --verbosity=7 --filter --no-host --width would be the minimum required information for us to be able to help you. (Personally Identifiable Information like serial numbers and MAC addresses will be filtered out by the above command)
Also, please copy-paste that output in-between 3 backticks ``` at the beginning and end of the code/text.
Make sure that you have the appropriate Linux headers installed for your kernel. Then install via pamac in terminal or pamac GUI. In addition, be certain that in a dual boot situation that Windows is completely shutdown (always) and hibernation and fast boot are disabled. Good Luck.
If you use tethering and need to keep down the downloaded data volume
just install flex and see if it will suffice (for the time being).
You could also connect your phone to the wlan - and then use usb tethering to get to use that
but I guess that is what you are doing already - so:
no issues with the amount of data …
update:
I searched up how to install headers but which should I choose
[sudo] password for kevinp:
:: There are 11 providers available for linux-headers:
:: Repository core
1) linux414-headers 2) linux419-headers 3) linux44-headers 4) linux49-headers 5) linux510-headers
6) linux515-headers 7) linux516-headers 8) linux517-headers 9) linux54-headers
:: Repository community
10) linux515-rt-headers 11) linux516-rt-headers
Enter a number (default=1):
of course you need the kernel headers
at least the ones for the kernel that you are running (and trying to build a loadable kernel module for) right now.
It looks like you are running 5.15, but the inxi is incomplete at the top. My original response noted to make sure that you have the appropriate kernel headers installed…
After carefully following the instructions I think I almost got,
I installed the right Header
I downloaded the dependencies (I think thats what they are called)
And Almost everything goes according to plan but as previously I previously said Im still getting the Kernel modules tree error. I dont know if this is of any help but here is what ive done,
Preparing...
Checking rtl8821au-dkms-git dependencies...
Resolving dependencies...
Checking inter-conflicts...
To install (11):
m4 1.4.19-1 core 264.5 kB
autoconf 2.71-1 core 660.7 kB
pkgconf 1.8.0-1 core 59.0 kB
flex 2.6.4-3 core 304.4 kB
gc 8.2.0-2 (Required By: make) extra 238.6 kB
guile 2.2.7-2 (Required By: make) extra 6.6 MB
make 4.3-3 core 493.2 kB
bison 3.8.2-1 core 803.5 kB
patch 2.7.6-8 core 94.7 kB
automake 1.16.5-1 core 627.5 kB
dkms 3.0.3-1 (Required By: rtl8821au-dkms-git) extra 37.1 kB
To build (1):
rtl8821au-dkms-git 5.12.5.2.r95.ge4ad4ba-1 AUR
Total download size: 10.2 MB
Total installed size: 57.3 MB
Edit build files : [e]
Apply transaction ? [e/y/N] y
Download of m4 (1.4.19-1) started
Download of flex (2.6.4-3) started
Download of m4 (1.4.19-1) finished
Download of gc (8.2.0-2) started
Download of flex (2.6.4-3) finished
Download of pkgconf (1.8.0-1) started
Download of pkgconf (1.8.0-1) finished
Download of autoconf (2.71-1) started
Download of gc (8.2.0-2) finished
Download of bison (3.8.2-1) started
Download of autoconf (2.71-1) finished
Download of make (4.3-3) started
Download of bison (3.8.2-1) finished
Download of guile (2.2.7-2) started
Download of make (4.3-3) finished
Download of dkms (3.0.3-1) started
Download of dkms (3.0.3-1) finished
Download of patch (2.7.6-8) started
Download of patch (2.7.6-8) finished
Download of automake (1.16.5-1) started
Download of automake (1.16.5-1) finished
Download of guile (2.2.7-2) finished
Checking keyring... [11/11]
Checking integrity... [11/11]
Loading packages files... [11/11]
Checking file conflicts... [11/11]
Checking available disk space... [11/11]
Installing m4 (1.4.19-1)... [1/11]
Installing flex (2.6.4-3)... [2/11]
Installing pkgconf (1.8.0-1)... [3/11]
Installing gc (8.2.0-2)... [4/11]
Installing autoconf (2.71-1)... [5/11]
Installing guile (2.2.7-2)... [6/11]
Installing bison (3.8.2-1)... [7/11]
Installing make (4.3-3)... [8/11]
Installing patch (2.7.6-8)... [9/11]
Installing dkms (3.0.3-1)... [10/11]
Installing automake (1.16.5-1)... [11/11]
Running post-transaction hooks...
Arming ConditionNeedsUpdate... [1/3]
Refreshing PackageKit... [2/3]
Updating the info directory file... [3/3]
Cloning rtl8821au-dkms-git build files...
Generating rtl8821au-dkms-git information...
Building rtl8821au-dkms-git...
==> Making package: rtl8821au-dkms-git 5.12.5.2.r95.ge4ad4ba-1 (Sat 05 Mar 2022 04:32:32 PM EST)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
-> Cloning 8821au-20210708 git repo...
Cloning into bare repository '/var/tmp/pamac-build-kevinp/rtl8821au-dkms-git/8821au-20210708'...
remote: Enumerating objects: 1294, done.
remote: Counting objects: 100% (1294/1294), done.
remote: Compressing objects: 100% (841/841), done.
remote: Total 1294 (delta 647), reused 1078 (delta 449), pack-reused 0
Receiving objects: 100% (1294/1294), 3.12 MiB | 87.00 KiB/s, done.
Resolving deltas: 100% (647/647), done.
-> Found dkms.conf
==> Validating source files with sha256sums...
8821au-20210708 ... Skipped
dkms.conf ... Passed
==> Removing existing $srcdir/ directory...
==> Extracting sources...
-> Creating working copy of 8821au-20210708 git repo...
Cloning into '8821au-20210708'...
done.
==> Starting pkgver()...
==> Updated version: rtl8821au-dkms-git 5.12.5.2.r125.g377d3ca-1
==> Entering fakeroot environment...
==> Starting package()...
==> Tidying install...
-> Removing libtool files...
-> Purging unwanted files...
-> Removing static library files...
-> Stripping unneeded symbols from binaries and libraries...
-> Compressing man and info pages...
==> Checking for packaging issues...
==> Creating package "rtl8821au-dkms-git"...
-> Generating .PKGINFO file...
-> Generating .BUILDINFO file...
-> Generating .MTREE file...
-> Compressing package...
==> Leaving fakeroot environment.
==> Finished making: rtl8821au-dkms-git 5.12.5.2.r125.g377d3ca-1 (Sat 05 Mar 2022 04:33:21 PM EST)
==> Cleaning up...
Checking keyring... [1/1]
Checking integrity... [1/1]
Loading packages files... [1/1]
Checking file conflicts... [1/1]
Checking available disk space... [1/1]
Installing rtl8821au-dkms-git (5.12.5.2.r125.g377d3ca-1)... [1/1]
Running post-transaction hooks...
Arming ConditionNeedsUpdate... [1/3]
Install DKMS modules [2/3]
==> ERROR: Missing 5.15.24-1-rt31-MANJARO kernel modules tree for module 8821au/5.12.5.2.r125.g377d3ca.
Refreshing PackageKit... [3/3]
Transaction successfully finished.
I removed my HDD where Manjaro was installed and made a fresh install on my SSD, I don’t know if this helps any but after doing that I’m behind on over 2.2 gigabytes of updates. And also I had to install the RT version of the header because the normal wouldn’t work.
And a huge thanks to everyone who has helped me so far!
so now:
if you want to use the AUR and dkms to build a kernel module that s not available in the standard way
you need to have: base-devel (the package group)
the kernel headers of each kernel that you have installed and that you want to build the module for
Welcome to Manjaro! 
to give us more information so we can see what’s really going on.
