opencv[world] seems to not actually build a standalone DLL

[jwezorek]

I'm trying to build a standalone opencv_world4.dll via
.\vcpkg.exe install opencv[world]:x64-windows
The build succeeds but the built DLL has dependencies on other DLLs (I can tell with dependency walker), unlike OpenCV's prebuilt binaries. More details here.

[Osyotr]

You need this https://learn.microsoft.com/en-us/vcpkg/users/triplets#per-port-customization

[jwezorek]

I need more information to understand how that helps.

Anyway, I'm building OpenCV from source now and when I set the "world" feature in CMake it indeed builds a DLL that has no dependencies, so it seems to me something is wrong with vcpkg's OpenCV package.

[Osyotr]

You're building with x64-windows triplet which builds everything as dynamic libraries, including all of the opencv dependencies.

Here's a quote from the doc linked above:

If you need to apply different settings for different libraries, you must make a single custom triplet with that combination of settings.
See Per-port customization below for how to accomplish this.

The doc also has an examples how to add and use custom triplets. Basically you need to set VCPKG_LIBRARY_LINKAGE to static but override it with dynamic for opencv. You probably would also need to set VCPKG_CRT_LINKAGE to static for everything (including opencv) if you don't want to depend on msvc DLLs.