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A lightweight graphical file manager in WSLg: Thunar on Ubuntu, RHEL 9 and NixOS

windows - 2026-10-15

WSLg is the part of WSL2 that shows Linux graphical applications as ordinary Windows windows. It's included in WSL on Windows 11 and recent Windows 10 builds, and it only works with WSL2 distributions, not WSL1. A WSL distribution has no file manager by default. That matters as soon as something asks to "open a folder", such as a browser's Show in folder: nothing happens, or you get an error.

Thunar, Xfce's file manager, is a light choice. It has few dependencies, and the same steps work on all three distributions. Only the package and its source change.

How "open this folder" is resolved

Linux desktop applications don't name a file manager. They ask for the default application for the MIME type inode/directory. A MIME type is a label for a kind of content, such as text/plain or image/png, and inode/directory means "a folder". The answer is the name of a .desktop file, the launcher description that every graphical application installs under /usr/share/applications/.

xdg-mime (from xdg-utils) reads and writes that default, in ~/.config/mimeapps.list:

xdg-mime default thunar.desktop inode/directory
xdg-mime query default inode/directory     # thunar.desktop

The command is the same on every distribution. Run it as your user, not with sudo, because the setting is per user.

Ubuntu

sudo apt install --no-install-recommends thunar xdg-utils
xdg-mime default thunar.desktop inode/directory
thunar &

--no-install-recommends leaves out the optional packages apt would add, which keeps the install small. On Ubuntu 24.04 this installs Thunar 4.18.8, and the launcher is /usr/share/applications/thunar.desktop.

RHEL 9 and rebuilds (Rocky, AlmaLinux)

Red Hat supports RHEL 9 on WSL2 for development and learning, with a subscription, including the free Developer subscription (Red Hat article 7115538). Thunar isn't in RHEL's own repositories. It comes from EPEL (Extra Packages for Enterprise Linux), a Fedora project that rebuilds extra packages for RHEL. Some EPEL packages need CRB (CodeReady Builder), a Red Hat repository of build dependencies that's off by default, so enable both:

# RHEL
sudo subscription-manager repos --enable codeready-builder-for-rhel-9-$(arch)-rpms
sudo dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm

# Rocky Linux or AlmaLinux instead
sudo dnf config-manager --set-enabled crb
sudo dnf install epel-release

sudo dnf install --setopt=install_weak_deps=False Thunar xdg-utils
xdg-mime default thunar.desktop inode/directory

The package name has a capital T (Thunar), but the launcher file doesn't. Check what's installed with ls /usr/share/applications | grep -i thunar. install_weak_deps=False is dnf's equivalent of apt's --no-install-recommends.

NixOS (NixOS-WSL)

On NixOS, software is declared in the system configuration, not installed with a command (see the first steps entry). The programs.thunar module installs Thunar and also turns on programs.xfconf, the settings store Thunar saves its preferences in:

programs.thunar = {
  enable = true;
  plugins = with pkgs; [ thunar-archive-plugin ];   # optional
};

# The default for folders, for every user
xdg.mime.defaultApplications."inode/directory" = "thunar.desktop";

Then run sudo nixos-rebuild switch. programs.thunar exists only as a NixOS option, not in Home Manager. If your user's settings live in Home Manager (the NixOS module entry explains how it's set up), set the default there instead. Its option has a different name:

xdg.mimeApps.enable = true;
xdg.mimeApps.defaultApplications."inode/directory" = "thunar.desktop";

NixOS-WSL makes the WSLg X11 socket available in /tmp/.X11-unix itself, and its wsl.startMenuLaunchers option adds the installed graphical applications to the Windows Start menu.

Without installing anything

To open folders in Windows Explorer instead, explorer.exe takes a Windows path, and wslpath -w converts a Linux path to one:

explorer.exe "$(wslpath -w ~/Downloads)"

That works by hand. It doesn't change what inode/directory opens, though, so applications that ask for a folder still need a .desktop file that calls Explorer.

A browser's "Show in folder"

On Ubuntu, the chromium-browser package is a stub that installs the Chromium snap instead. Snaps are sandboxed packages run by snapd, which needs systemd. A sandboxed browser doesn't start the file manager directly. It asks the XDG desktop portal, a D-Bus service that applications in a sandbox use to reach the desktop, so Show in folder also needs xdg-desktop-portal and a D-Bus session. A browser installed as a deb, such as Google Chrome, calls the inode/directory default directly.

Sources

Created 2026-10-15T17:18:13+02:00 · Edit