Here are the best practices for running GUI applications of Cygwin on Windows 10/11:
Install X Server
Select an X Server: There are several X servers available for Windows, such as Xming, VcXsrv, and Cygwin's built - in X server. Xming and VcXsrv are popular choices due to their ease of use and good performance. You can download them from their official websites. If you prefer to use Cygwin's built - in X server, make sure to select the relevant package during the Cygwin installation.
Install the X Server: Follow the installation wizard of the selected X server to complete the installation. For example, when installing Xming, simply run the installer and accept the default settings.
Install Required Packages in Cygwin
Launch the Cygwin Setup Program: Run the Cygwin setup - x86_64.exe (for 64 - bit Windows) or setup - x86.exe (for 32 - bit Windows) to start the installation process.
Select Packages: In the "Select Packages" window, expand categories like "X11" and "Devel". Select packages related to the GUI applications you want to run, such as "xorg - server", "xinit", and development - related packages like "gcc - core", "gcc - g++", and "make". If you plan to use specific GUI libraries or frameworks, make sure to install their corresponding development packages as well.
Configure Environment Variables
Set DISPLAY Variable: In the Cygwin terminal, set the DISPLAY variable to specify the address of the X server. If the X server is running on the local machine, the value is usually :0. For example, you can add the following line to the .bashrc or .profile file in your home directory: export DISPLAY=:0. If the X server is running on a remote machine, set it to the IP address and display number of the remote X server, like export DISPLAY=192.168.1.100:0.
Add Cygwin Bin Directory to PATH: Ensure that the Cygwin bin directory is included in the system's PATH environment variable. This allows you to run Cygwin commands and applications from any directory. If you installed Cygwin in the default directory, the path is usually C:\cygwin64\bin (for 64 - bit Cygwin) or C:\cygwin\bin (for 32 - bit Cygwin). You can add it to the PATH variable in the Windows system settings or in the Cygwin terminal by running export PATH=/usr/local/bin:/usr/bin:/bin:$PATH.
Start the GUI Application
Start the X Server: Before running the GUI application, start the X server. For example, if you are using Xming, launch the Xming program from the start menu.
Launch the GUI Application: In the Cygwin terminal, navigate to the directory where the GUI application is located or use the command - line to directly run the application. For example, if you want to run the xclock application, simply type xclock in the Cygwin terminal. The GUI application window should then appear on the screen.
Troubleshooting
Check for Error Messages: If the GUI application fails to start or shows an error, check the error messages in the Cygwin terminal. The error messages usually provide useful information about the problem, such as missing dependencies or incorrect configurations.
Verify X Server and Cygwin Compatibility: Make sure that the X server and Cygwin versions are compatible. Some older X servers may not work well with the latest Cygwin version, and vice versa. If possible, update both the X server and Cygwin to their latest versions.
Check Firewall Settings: Windows Firewall or other security software may block the connection between Cygwin and the X server. Temporarily disable the firewall or add exceptions for the X server and Cygwin programs to see if it resolves the issue.