Gurobi Search Path does not include current folder

[sfiruch]

What version of OR-Tools and what language are you using?
Version: 9.6.2534
Language: C#

Which solver are you using (e.g. CP-SAT, Routing Solver, GLOP, BOP, Gurobi)
Gurobi

What operating system (Linux, Windows, ...) and version?
Windows 11 (22621.1555)

What did you do?

1. Place gurobi100.dll, gurobi100.NET.dll and gurobi.lic in a folder
2. Compile and run the following C# program in the same folder:

using var m = Solver.CreateSolver("Gurobi");

What did you expect to see
No error message

What did you see instead?

WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
W0000 00:00:1683214867.234411    6748 linear_solver.cc:644] Support for Gurobi not linked in, or the license was not found.

Only when I copy the libraries to the folder C:\Program Files\gurobi1000\win64\bin, the application works without error. Apparently, the application searches in these hardcoded paths for the Gurobi libraries, but not the current directory:

Anything else we should know about your project / environment
It's common practice under Windows to colocate DLLs with the application executable.

[lperron]

You can pass the exact path of the library.

[sfiruch]

Correct. It caught me by surprise, because it doesn't behave like other Win32 libraries. The "normal" search order is documented here: https://learn.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-search-order#standard-search-order-for-packaged-apps

[lperron]

On unix, it is not recommended to search on the current dir.
I need to patch gurobi/environment.cc

[lperron]

and pushed to main.

[sfiruch]

Thanks!!