9d9ad753f3
.. since Qt5.15 QtConcurrent::map() will use all available worker threads in the global thread pool. And this causes a deadlock in the GUI since QGraphicsView uses threads to manage updates. .. we now manage the metric refresh via RideCacheRefreshThread and use at most 50% of the overall threads available in the global thread pool. .. Have tested obvious triggers such as metric schema updates and user metrics being changed, but more testing is needed. Fixes #3611
GoldenCheetah
About
GoldenCheetah is a desktop application for cyclists and triathletes and coaches, providing a rich set of tools and models to analyse, track and predict performance, optimise aerodynamics and train indoors.
GoldenCheetah integrates with most popular cloud services like Strava and Todays Plan, imports data from bike computers, imports downloads from any website like TrainingPeaks and Garmin and will also connect to smart trainers using ANT+ and Bluetooth.
GoldenCheetah is free for everyone to use and modify, released under the GPL v2 open source license with pre-built binaries for Mac, Windows and Linux.
Installing
Golden Cheetah install and build instructions are documented for each platform;
INSTALL-WIN32 For building on Microsoft Windows
INSTALL-LINUX For building on Linux
INSTALL-MAC For building on Apple OS X
macOS and Linux: 
Windows:
Official release builds, snapshots and development builds are all available from http://www.goldencheetah.org
NOTIO Fork
If you are looking for the NOTIO fork of GoldenCheetah it can be found here: https://github.com/notio-technologies/GCNotio