Pinging @Arech for response. Could you please help to test this PR on your machine? I added patch as your comment for opencv3 and opencv4.

Thanks Lily! I'll try it in the next few hours and will get back to you with the results.
I've never tried ports from a non-main branch of the vcpkg repo. Do I assume correctly, that I just need to use your latest commit hash as the repo baseline? f3a13da28514f7abfea91b36b93157b68fd46921 right? If I'm wrong may be you can point me to a guideline how to do the testing correctly?
On the surface your changes seems to be exactly what I had suggested, so I expect it to work (but I'll test!)

erm, with that commit as a baseline, it installs previous port 4.8.0#11. It turns out that the latest commit is the second one - fc0a58d5ed897321be0759e4d4ff66f921eeca97, however, when I use it as a baseline I get "error: no version database entry for opencv4 at 4.8.0#12".
I can of course checkout it locally and use as an overlay port, but that would be not much different from my own overlay port, which I posted in the issue. So it's probably not the best option.
I've never dealt with testing vcpkg PRs, can you please suggest me, how do I do that with manifest mode?

erm, with that commit as a baseline, it installs previous port 4.8.0#11. It turns out that the latest commit is the second one - fc0a58d5ed897321be0759e4d4ff66f921eeca97, however, when I use it as a baseline I get "error: no version database entry for opencv4 at 4.8.0#12". I can of course checkout it locally and use as an overlay port, but that would be not much different from my own overlay port, which I posted in the issue. So it's probably not the best option. I've never dealt with testing vcpkg PRs, can you please suggest me, how do I do that with manifest mode?

Thanks for your work. You could clone my repository https://github.com/LilyWangLL/vcpkg.git and switch to branch dev/LilyWang/issue35209. Then use your vcpkg.json to test this PR. Thanks in anvance.

@LilyWangLL can confirm it finally compiles and works on QNX with my usecase

"dependencies": [
   ...,
  {
    "name": "opencv4",
    "default-features": false,
    "features": [ "jpeg", "png", "ffmpeg" ]
  },
}

Documenting the steps here for Googlers on how to test vcpkg branch, b/c there are few non-usual things:

1. Clone the repo https://github.com/LilyWangLL/vcpkg.git, checkout the dev/LilyWang/issue35209 branch:

~/tmp/vcpkg$ git status
On branch dev/LilyWang/issue35209
Your branch is up to date with 'origin/dev/LilyWang/issue35209'.

nothing to commit, working tree clean
~/tmp/vcpkg$ git rev-parse HEAD
fc0a58d5ed897321be0759e4d4ff66f921eeca97

2. in the vcpkg.json of the test project update the main repo and set the reference field for it:

"vcpkg-configuration": {
  "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/main/docs/vcpkg-configuration.schema.json",
  "default-registry": {
    "kind": "git",
    "repository": "https://github.com/LilyWangLL/vcpkg",
    "reference": "dev/LilyWang/issue35209",
    "baseline": "fc0a58d5ed897321be0759e4d4ff66f921eeca97"
  },
}

3. Now run CMake to build the project using this cloned ~/tmp/vcpkg instance

Thanks for the fix :)