libpfc isn't building on Arch Linux

[travisdowns]

libpfc isn't building on Arch Linux

[travisdowns]

As far as I know, this is the "standard" way to build a kernel module. There should be a directory called build in /usr/lib/modules/4.12.8-2-ARCH/, and then make is invoked there with the modules target (which is a standard target defined by the kernel module build infra, it doesn't come from this project).

What does your /lib/modules/ tree look like? You mention /usr/lib/modules/4.12.8-2-ARCH/ but the build is trying to use /lib/modules/4.12.8-2-ARCH/build (no /usr/*).

Here's some info from my Ubuntu 16.04 system:

ls /lib/modules/
4.10.0-33-generic  4.10.0-35-generic  4.10.0-37-generic  4.4.0-93-generic  4.4.0-96-generic  4.4.0-97-generic
ls -l /lib/modules/4.10.0-37-generic/build
lrwxrwxrwx 1 root root 40 Oct  6 18:40 /lib/modules/4.10.0-37-generic/build -> /usr/src/linux-headers-4.10.0-37-generic

Here's info on building kernel modules on Arch. It seems to follow the pattern above. Check that you have the dependencies installed, like base-devel and linux-headers?

[travisdowns]

Actually after taking a better look at the link I gave above, it seems you need to do a bit of work to get the source needed to build the kernel module. See the part under "Source configuration" here. Once you do that, it should work.

[pcordes]

Silly me, I didn't have linux-headers installed. Probably I don't have that on the Ubuntu machine either. I guess I was expecting the error message to be something different if that was the problem.

On Arch, /lib is a symlink to /usr/lib by default. You could change that if you wanted to have /usr not on the root FS. That's why pwd finds /usr/lib/...

$ ll /lib/modules/4.12.8-2-ARCH/build/
total 23M
-rw-r--r-- 1 root root 29M Aug 18 11:09 vmlinux

So yes there is a build directory, even without linux-headers installed.

Arch is a rolling-release distro, so headers for the kernel I'm running aren't still available in the main repos. I'll have to remember to install kernel headers next time I'm ready to reboot and upgrade my kernel (+ the rest of the system).

[travisdowns]

Closing this as @pcordes confirmed above the issue was missing kernel module build environment on the local box.