I'm trying to set up goroot in wls2 Goland,but ut something went wrong: "The selected directory is not a valid home for Go SDK"
What should I do
At the moment, as of 2020.1.3, you cannot. See the issue that tracks this request and vote/watch it for updates.
October 2021 update.
Go SDK under WSL2 is supported in GoLand since 2021.3 (it reaches Early Access Program at the moment). GoLand suggests selecting Go SDK on WSL2 mount if the location of the project is on WSL2 as well.
I found out my issue was having the go source code in c:\ drive. It must be in WSL2 mnt to work correctly. Tested on GoLand 2021.3.1