[Ports Overlay] New feature draft spec (Superseded by #6981)

[vicroms]

This is a specification draft for a new feature.

This document proposes adding a new option --overlay-ports to the vcpkg install, vcpkg update, and vcpkg upgrade commands to specify additional paths containing ports.
These locations will be searched when resolving port names during package installation, and override ports in <vcpkg-root>/ports.

Any feedback is welcomed.

[martin-s]

I appreciate the draft, but two questions come to my mind:

• Example Add libogg/libvorbis/libvorbisfile #1: where is the installed folder created? Is there one installed folder or more?

• what about vcpkg depend-info? When ports are splitted over different folders, I would like to have a dependency graph as well.

[vicroms]

Hi @martin-s

• Example Add libogg/libvorbis/libvorbisfile #1: where is the installed folder created? Is there one installed folder or more?

There's still just one installed folder, its location remains the same <vcpkg-root>/installed/<triplet>.

• what about vcpkg depend-info? when port are split over different folders, I would like to have a dependency graph as well.

Noted, vcpkg depend-info should also accept the --overlay-ports option.

[cenit]

Developer Alice and her team use vcpkg to acquire OpenCV and some other packages. She has even contributed many patches to add features to the OpenCV 3 port in vckpg. But, one day, she notices that a PR to update OpenCV to the next major version has been merged.

A long time ago in a galaxy far, far away...

the upgrade to OpenCV 4 really hurts deep inside, it seems you are not safe 🤣

apart from that, this is a really nice feature. Thanks for your work on it!!! It will be terrific for vcpkg deployment in many situations!

[vicroms]

Superseded by #6981