wsl2 fail to build kernel

[yoshino-polyu]

Windows Version

Microsoft Windows [Version 10.0.23451.1000]

WSL Version

1.2.5.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

5.15.90.1

Distro Version

Ubuntu 18.04 LTS

Other Software

No response

Repro Steps

go to https://github.com/microsoft/WSL2-Linux-Kernel

run sudo apt install build-essential flex bison dwarves libssl-dev libelf-dev in wsl2, no problems exist
run make KCONFIG_CONFIG=Microsoft/config-wsl in wsl2, output:
make: *** No targets specified and no makefile found. Stop.

Expected Behavior

go to https://github.com/microsoft/WSL2-Linux-Kernel

run sudo apt install build-essential flex bison dwarves libssl-dev libelf-dev in wsl2, no problems exist
run make KCONFIG_CONFIG=Microsoft/config-wsl in wsl2, output:
make: *** No targets specified and no makefile found. Stop.

Actual Behavior

go to https://github.com/microsoft/WSL2-Linux-Kernel

run sudo apt install build-essential flex bison dwarves libssl-dev libelf-dev in wsl2, no problems exist
run make KCONFIG_CONFIG=Microsoft/config-wsl in wsl2, output:
make: *** No targets specified and no makefile found. Stop.

Diagnostic Logs

No response

[elsaco]

@yoshino-polyu where are you invoking make from? Looks like it can't locate the Makefile. The latest WSL2 kernel extracts to WSL2-Linux-Kernel-linux-msft-wsl-6.1.21.2 and if you didn't rename the directory start the build process there:

elsaco@ubuntu:~/WSL2-Linux-Kernel-linux-msft-wsl-6.1.21.2$ make KCONFIG_CONFIG=Microsoft/config-wsl
  SYNC    include/config/auto.conf.cmd
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  HOSTCC  scripts/kconfig/confdata.o
---cut---

I usually specify a target to make:

elsaco@ubuntu:~/WSL2-Linux-Kernel-linux-msft-wsl-6.1.21.2$ make KCONFIG_CONFIG=Microsoft/config-wsl bzimage

and this will build a compressed kernel.

[yoshino-polyu]

Thanks. Actually, I didn't know where my WSL2 kernel extracts to, and Google gives C:\WINDOWS\System32\lxss\tools\kernel , which is definitely not what you said (~/WSL2-Linux-Kernel-linux-msft-wsl-6.1.21.2). I also use the command find / -name "WSL2-Linux-Kernel-linux*" -print 2>/dev/null to search that file, but output shows nothing.