From 927bb1985fb4ab92392c24571605af800f0cdcbe Mon Sep 17 00:00:00 2001
From: David Rowe <david@ctrlaltstudio.com>
Date: Sun, 12 Apr 2020 13:43:36 +1200
Subject: [PATCH] Add support for Linux custom Qt builds

Credit: Dale Glass <dale@daleglass.net>
---
 BUILD_LINUX.md | 10 ++++++++++
 hifi_qt.py     |  6 +++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/BUILD_LINUX.md b/BUILD_LINUX.md
index b549d222da..f88e7173c8 100644
--- a/BUILD_LINUX.md
+++ b/BUILD_LINUX.md
@@ -89,6 +89,16 @@ Then checkout the main branch with:
 git checkout kasen/core
 ```
 
+### Using a custom Qt build
+
+Qt binaries are only provided for Ubuntu. In order to build on other distributions, a Qt5 install needs to be provided as follows:
+
+* Set `VIRCADIA_USE_PREBUILT_QT=1`
+* Set `VIRCADIA_USE_QT_VERSION` to the Qt version (defaults to `5.12.3`)
+* Set `HIFI_QT_BASE=/path/to/qt`
+
+Qt must be installed in `$HIFI_QT_BASE/$VIRCADIA_USE_QT_VERSION/qt5-install`.
+
 ### Compiling
 
 Create the build directory:
diff --git a/hifi_qt.py b/hifi_qt.py
index 3894354033..bfde8e5532 100644
--- a/hifi_qt.py
+++ b/hifi_qt.py
@@ -28,7 +28,7 @@ endif()
     def __init__(self, args):
         self.args = args
         self.configFilePath = os.path.join(args.build_root, 'qt.cmake')
-        self.version = '5.12.3'
+        self.version = os.getenv('VIRCADIA_USE_QT_VERSION', '5.12.3')
 
         self.assets_url = self.readVar('EXTERNAL_BUILD_ASSETS')
 
@@ -48,6 +48,10 @@ endif()
 
         self.lockFile = os.path.join(lockDir, lockName)
 
+        if (os.getenv('VIRCADIA_USE_PREBUILT_QT')):
+            print("Using pre-built Qt5")
+            return
+
         # OS dependent information
         system = platform.system()