setup_docs: Add troubleshooting steps for WSL2.

This commit adds steps to troubleshoot errors encountered
because of certain services like postgresql not starting
on WSL2.

The common reason behind this is port conflicts with other
services running on some other WSL2 instance or the host
Windows system.

This commit provides a guide to handle these issues, and
also provides some additional tips to WSL2 users to avoid
facing these issues in the future.

Fixes #32718.

docs/development/setup-recommended.md

@@ -752,6 +752,15 @@ WSL instance) is also usually helpful.
 
 ::::{tab-set}
 
+:::{tab-item} Windows (WSL)
+:sync: os-windows
+
+```{include} setup/wsl-troubleshoot.md
+
+```
+
+:::
+
 :::{tab-item} Windows (VM)
 :sync: os-windows-vm
 

docs/development/setup/wsl-troubleshoot.md

@@ -0,0 +1,75 @@
+WSL2 users often encounter issues where services fail to start or remain inactive. Follow the steps below to diagnose and resolve such problems.
+
+#### 1. Check the Status of the Service
+
+To verify if a service is running, use the following command:
+
+```console
+$ systemctl status <service_name>
+```
+
+If the service is inactive, you can attempt to start it with:
+
+```console
+$ systemctl start <service_name>
+```
+
+#### 2. Diagnose Port Conflicts
+
+Services like `postgresql` may fail to start due to port conflicts. These conflicts can be caused by:
+
+- Other services running in Windows.
+- Services running in another WSL2 instance.
+
+#### Resolving Port Conflicts with Other WSL Instances
+
+To resolve port conflicts with another WSL2 instance, stop the conflicting instance using the following command:
+
+```console
+> wsl -t <WSL_Instance_Name>
+```
+
+After stopping the conflicting instance, restart your WSL instance with:
+
+```console
+> wsl -d <Your_Zulip_Instance_Name>
+```
+
+#### Resolving Port Conflicts with Services Running on Windows
+
+To resolve conflicts caused by Windows processes:
+
+1. Identify the process using the conflicting port by running:
+
+```console
+> Get-Process -Id (Get-NetTCPConnection -LocalPort <your_port_number>).OwningProcess
+```
+
+2. If a process is found, terminate it using:
+
+```console
+> taskkill /PID <pid> /F
+```
+
+3. Restart the Service or Enable Auto-Start
+
+After resolving port conflicts, try restarting the service using:
+
+```console
+$ systemctl start <service_name>
+```
+
+To ensure the service always starts on boot, enable it with:
+
+```console
+$ systemctl enable <service_name>
+```
+
+---
+
+#### Additional Tips
+
+- Use `wsl --list` to view all running WSL2 instances and their states.
+- Avoid overlapping port usage between WSL2 instances and Windows processes.
+- Keep a record of services and their associated port numbers to prevent conflicts in the future.
+- Ensure that you use a fresh WSL instance to setup the Zulip development environment to avoid dependency conflicts.