OpenBSD is not officially supported. These instructions are not actively updated and represent what happened to work as recently as May 2024 on OpenBSD 7.5 amd64.
Games do not currently work on OpenBSD/amd64 due to bug 10926. Until/unless a better solution is devised, users can apply a patch like the following to get past the bug:
Install the required packages. Keep in mind this is an incomplete list for a maximal build, the actual list of dependencies may be smaller depending on which features are enabled. Please amend as needed:
To build, run the following in the repository root directory:
Other considerations:
- Dolphin needs a lot of memory to run - more than OpenBSD's default limits allow. Increase the 
datasize limits for your login class to at least 4G in /etc/login.conf, or (assuming your login class's datasize-max limit permits this) run ulimit -d 4194304 before running Dolphin, e.g. in your ~/.profile file or in a Dolphin startup script. 
- To improve performance, you may want to add 
-DCMAKE_CXX_FLAGS=-Ofast to the above CMake invocation when building.