`libexpat1-dev` CMake configuration error

[Sandi Vujaković]

Using the package provided by Ubuntu Impish results in the following CMake configuration error when trying to build OpenColorIO:

```
[…]
CMake Error in src/OpenColorIO/CMakeLists.txt:
  Imported target "expat::expat" includes non-existent path

    "/usr/lib/include"

  in its INTERFACE_INCLUDE_DIRECTORIES. Possible reasons include:

  * The path was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and references files it does not
  provide.
[…]
```

This wasn't an issue in Ubuntu Hirsute as far as I can recall and is not an issue when using the ASWF-provided packages — CMake flag `-DOCIO_INSTALL_EXT_PACKAGES=ALL`. A patch is attached that allows OpenColorIO to build using system-provided packages.

Further information in the related ticket in the OpenColorIO repository: https://github.com/AcademySoftwareFoundation/OpenColorIO/issues/1415#issuecomment-1003826550

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "`libexpat1-dev` patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Sandi Vujaković (elsandosgrande)]

This seems to be an upstream issue: https://github.com/libexpat/libexpat/issues/501

With that said, it doesn't seem like an upstream fix is likely any time soon, as is suggested by this comment by one of the members of the `libexpat` GitHub team on this NixOS pull request addressing this issue: https://github.com/NixOS/nixpkgs/pull/128997#issuecomment-873137856

NixOS seems to have a custom packaging setup, so the fix above is most likely not applicable.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Andrew Aitchison (werdnakendal)]

https://github.com/OSGeo/gdal/issues/5324 is a result of this and the upstream https://github.com/libexpat/libexpat/issues/501