Cannot compile 0.84 without default features

[HollayHorvath]

I'm trying to compile this crate with default features disabled (on my original project I have features2d enabled, but it's irrelevant for the repro) and I'm facing the following error:

error[E0277]: the trait bound `manual::core::ptr::Ptr<f32>: manual::core::ptr::ptr_extern::PtrExtern` is not satisfied
  --> ~/.cargo/registry/src/index.crates.io-6f17d22bba15001f/opencv-0.84.4/src/manual/core/ptr/ptr_f32.rs:6:18
   |
6  | impl Default for Ptr<f32> {
   |                  ^^^^^^^^ the trait `manual::core::ptr::ptr_extern::PtrExtern` is not implemented for `manual::core::ptr::Ptr<f32>`
   |
   = help: the following other types implement trait `manual::core::ptr::ptr_extern::PtrExtern`:
             manual::core::ptr::Ptr<Algorithm>
             manual::core::ptr::Ptr<ConjGradSolver>
             manual::core::ptr::Ptr<DownhillSolver>
             manual::core::ptr::Ptr<FileStorage>
             manual::core::ptr::Ptr<GpuMat_Allocator>
             manual::core::ptr::Ptr<MinProblemSolver>
             manual::core::ptr::Ptr<MinProblemSolver_Function>
             manual::core::ptr::Ptr<hub::core::Formatted>
             manual::core::ptr::Ptr<hub::core::Formatter>
note: required by a bound in `manual::core::ptr::Ptr`
  --> ~/.cargo/registry/src/index.crates.io-6f17d22bba15001f/opencv-0.84.4/src/manual/core/ptr.rs:19:8

(the same is recurring for Deref, DerefMut and Debug)

If I enable the stitching feature, the error goes away.

I tested with different versions and the last version that works without the stitching feature flag is 0.83.0, it seems that 0.84.0 introduced this error.

I doubt that it's relevant, but here are my details:

1. OS: Ubuntu 22.04 (Linux Mint 21.2)
2. OpenCV install: package manager
3. OpenCV version: 4.5.4
4. rustc version: rustc 1.71.1 (eb26296b5 2023-08-03)
5. Full output of clean build

[twistedfall]

Can you please check the beta branch to see if it fixes the issue?

[HollayHorvath]

Yes, the beta branch fixes this issue (just for the sake of completeness, master is having the same issue as 0.84)

[twistedfall]

Thanks for testing! Yep, master is expected to fail too. I will release the new crate version as soon as the CI finishes (successfully).

[twistedfall]

This is now released in 0.84.5