From 88486bd8631e2d705e55da5a4a65974b2b37b0cb Mon Sep 17 00:00:00 2001
From: Allison Thackston <73732028+althack@users.noreply.github.com>
Date: Sat, 15 Aug 2026 21:10:25 -0700
Subject: [PATCH] Make software GL configuration boolean

---
 features/src/linux-x11-forwarding/README.md            |  2 +-
 .../src/linux-x11-forwarding/devcontainer-feature.json | 10 +++-------
 features/src/linux-x11-forwarding/install.sh           |  8 ++++++--
 .../test/linux-x11-forwarding/host_forwarding_env.sh   |  2 +-
 features/test/linux-x11-forwarding/scenarios.json      | 10 +++++++++-
 .../test/linux-x11-forwarding/software_gl_disabled.sh  |  2 +-
 .../test/linux-x11-forwarding/software_gl_enabled.sh   |  9 +++++++++
 features/test/linux-x11-forwarding/test.sh             |  2 +-
 8 files changed, 31 insertions(+), 14 deletions(-)
 create mode 100755 features/test/linux-x11-forwarding/software_gl_enabled.sh

diff --git a/features/src/linux-x11-forwarding/README.md b/features/src/linux-x11-forwarding/README.md
index f169dcb..9e0da3e 100644
--- a/features/src/linux-x11-forwarding/README.md
+++ b/features/src/linux-x11-forwarding/README.md
@@ -16,7 +16,7 @@ Forward a local Linux host's X11 display into a development container.
 | Options Id | Description | Type | Default Value |
 |-----|-----|-----|-----|
 | x11Display | Set DISPLAY for X11 clients launched from the container. | string | :0 |
-| softwareGL | Set LIBGL_ALWAYS_SOFTWARE for GPU compatibility. | string | 1 |
+| softwareGL | Force Mesa software rendering with LIBGL_ALWAYS_SOFTWARE=1. | boolean | false |
 
 ## Linux host requirements
 
diff --git a/features/src/linux-x11-forwarding/devcontainer-feature.json b/features/src/linux-x11-forwarding/devcontainer-feature.json
index 609de15..96eb982 100644
--- a/features/src/linux-x11-forwarding/devcontainer-feature.json
+++ b/features/src/linux-x11-forwarding/devcontainer-feature.json
@@ -12,13 +12,9 @@
       "description": "Set DISPLAY for X11 clients launched from the container."
     },
     "softwareGL": {
-      "type": "string",
-      "default": "1",
-      "proposals": [
-        "0",
-        "1"
-      ],
-      "description": "Set LIBGL_ALWAYS_SOFTWARE for GPU compatibility."
+      "type": "boolean",
+      "default": false,
+      "description": "Force Mesa software rendering with LIBGL_ALWAYS_SOFTWARE=1."
     }
   },
   "containerEnv": {
diff --git a/features/src/linux-x11-forwarding/install.sh b/features/src/linux-x11-forwarding/install.sh
index 318df6f..914ff39 100755
--- a/features/src/linux-x11-forwarding/install.sh
+++ b/features/src/linux-x11-forwarding/install.sh
@@ -2,7 +2,7 @@
 set -euo pipefail
 
 x11_display="${X11DISPLAY:-:0}"
-software_gl="${SOFTWAREGL:-1}"
+software_gl="${SOFTWAREGL:-false}"
 
 cat >/etc/profile.d/devcontainer-x11-gui.sh <<EOF
 host_runtime_dir="/tmp/devcontainer-host-runtime"
@@ -28,7 +28,11 @@ else
 fi
 
 export DISPLAY="${x11_display}"
-export LIBGL_ALWAYS_SOFTWARE="${software_gl}"
+if [ "${software_gl}" = "1" ] || [ "${software_gl}" = "true" ]; then
+    export LIBGL_ALWAYS_SOFTWARE=1
+else
+    unset LIBGL_ALWAYS_SOFTWARE
+fi
 export QT_QPA_PLATFORM="xcb"
 export XAUTHORITY="\${xauthority_target}"
 EOF
diff --git a/features/test/linux-x11-forwarding/host_forwarding_env.sh b/features/test/linux-x11-forwarding/host_forwarding_env.sh
index 3d17405..d35129b 100755
--- a/features/test/linux-x11-forwarding/host_forwarding_env.sh
+++ b/features/test/linux-x11-forwarding/host_forwarding_env.sh
@@ -5,7 +5,7 @@ source dev-container-features-test-lib
 
 check "DISPLAY can be overridden from feature option" bash -lc '[ "${DISPLAY:-}" = ":99" ]'
 check "XAUTHORITY stays on fixed path" bash -c '[ "${XAUTHORITY:-}" = "/tmp/devcontainer-xauthority" ]'
-check "software rendering defaults through shell init" bash -lc '[ "${LIBGL_ALWAYS_SOFTWARE:-}" = "1" ]'
+check "software rendering is not forced by default" bash -lc '[ -z "${LIBGL_ALWAYS_SOFTWARE:-}" ]'
 check "Qt uses the X11 backend by default" bash -lc '[ "${QT_QPA_PLATFORM:-}" = "xcb" ]'
 check "x11 socket directory is mounted" mountpoint -q /tmp/.X11-unix
 check "runtime directory is mounted" mountpoint -q /tmp/devcontainer-host-runtime
diff --git a/features/test/linux-x11-forwarding/scenarios.json b/features/test/linux-x11-forwarding/scenarios.json
index d2a5084..26f8640 100644
--- a/features/test/linux-x11-forwarding/scenarios.json
+++ b/features/test/linux-x11-forwarding/scenarios.json
@@ -14,7 +14,15 @@
     "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
     "features": {
       "linux-x11-forwarding": {
-        "softwareGL": "0"
+        "softwareGL": false
+      }
+    }
+  },
+  "software_gl_enabled": {
+    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+    "features": {
+      "linux-x11-forwarding": {
+        "softwareGL": true
       }
     }
   }
diff --git a/features/test/linux-x11-forwarding/software_gl_disabled.sh b/features/test/linux-x11-forwarding/software_gl_disabled.sh
index 7cdef90..13a2465 100755
--- a/features/test/linux-x11-forwarding/software_gl_disabled.sh
+++ b/features/test/linux-x11-forwarding/software_gl_disabled.sh
@@ -3,7 +3,7 @@ set -e
 
 source dev-container-features-test-lib
 
-check "software rendering can be disabled through shell init" bash -lc '[ "${LIBGL_ALWAYS_SOFTWARE:-}" = "0" ]'
+check "software rendering remains unset when disabled" bash -lc '[ -z "${LIBGL_ALWAYS_SOFTWARE:-}" ]'
 check "Qt uses the X11 backend by default" bash -lc '[ "${QT_QPA_PLATFORM:-}" = "xcb" ]'
 check "x11 socket directory is mounted" mountpoint -q /tmp/.X11-unix
 check "runtime directory is mounted" mountpoint -q /tmp/devcontainer-host-runtime
diff --git a/features/test/linux-x11-forwarding/software_gl_enabled.sh b/features/test/linux-x11-forwarding/software_gl_enabled.sh
new file mode 100755
index 0000000..ecbd437
--- /dev/null
+++ b/features/test/linux-x11-forwarding/software_gl_enabled.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+set -e
+source dev-container-features-test-lib
+
+check "software rendering can be enabled through shell init" bash -lc '[ "${LIBGL_ALWAYS_SOFTWARE:-}" = "1" ]'
+check "Qt uses the X11 backend by default" bash -lc '[ "${QT_QPA_PLATFORM:-}" = "xcb" ]'
+
+reportResults
diff --git a/features/test/linux-x11-forwarding/test.sh b/features/test/linux-x11-forwarding/test.sh
index 9b75fc5..81315ab 100755
--- a/features/test/linux-x11-forwarding/test.sh
+++ b/features/test/linux-x11-forwarding/test.sh
@@ -5,7 +5,7 @@ source dev-container-features-test-lib
 
 check "DISPLAY defaults to :0" bash -lc '[ "${DISPLAY:-}" = ":0" ]'
 check "XAUTHORITY is set to fixed path" bash -c '[ "${XAUTHORITY:-}" = "/tmp/devcontainer-xauthority" ]'
-check "software rendering defaults through shell init" bash -lc '[ "${LIBGL_ALWAYS_SOFTWARE:-}" = "1" ]'
+check "software rendering is not forced by default" bash -lc '[ -z "${LIBGL_ALWAYS_SOFTWARE:-}" ]'
 check "Qt uses the X11 backend by default" bash -lc '[ "${QT_QPA_PLATFORM:-}" = "xcb" ]'
 check "XDG runtime directory is private and writable" bash -lc '[ "${XDG_RUNTIME_DIR:-}" = "/tmp/devcontainer-runtime-$(id -u)" ] && [ -d "${XDG_RUNTIME_DIR}" ] && [ -w "${XDG_RUNTIME_DIR}" ] && [ "$(stat -c %a "${XDG_RUNTIME_DIR}")" = "700" ]'
 check "x11 socket directory exists" bash -c '[ -d /tmp/.X11-unix ]'