I upgraded some computers from openSUSE leap 15.3 to 15.4 and have noticed something new.
On the 15.3 machines across the top it says "BOINC Manager".
On the 15.4 machines across the top it says "BOINC Manager (Pre-release)".
Is there a reason for this? Is there something I should do about it?

I upgraded some computers from openSUSE leap 15.3 to 15.4 and have noticed something new.
On the 15.3 machines across the top it says "BOINC Manager".
On the 15.4 machines across the top it says "BOINC Manager (Pre-release)".
Is there a reason for this? Is there something I should do about it?

It just means the maintainers of the 15.4 release have decided the pre-release version is robust enough to use. I have been using the latest Master from Git-hub for a few years now and compiling my own and am yet to come across significant problems from it apart from once an upgrade of the OS borked things due to incompatible libraries. I wouldn't see it as anything to worry about.

It just means the maintainers of the 15.4 release have decided the pre-release version is robust enough to use.

There is no pre-release version, the pre-release title just means the maintainers built the client and manager using the -debug flag instead of the -release flag. It shouldn't mean much for the running of the programs, only if something breaks and crashes that it leaves behind debug information.

The question is: which version of the source code did they use?

Did they use the master branch, (potential) bugs and all, or did they use the client_release/7/7.20 branch?

Pre-release status is actually set in line 27 of version.h

Currently:
master is at v7.21.0, pre-release
branch is at v7.20.0, release

Pre-release status is actually set in line 27 of version.h

Yeah okay, but it is a compile flag, not a specific code version. That's what I meant.