Re: Include h3-pg extension

Re: Devrim Gündüz
> There are some overlapping files between h3 and h3-pg. I did not check
> closely, but you may not have to package h3. Just a FYI.

It took me a while to figure out because it was hidden in an
unexpected location, but the reason h3-pg can be compiled without h3
is that it downloads it at build time:

CMakeLists.txt:
# Include core library
add_subdirectory(cmake/h3)

cmake/h3/CMakeLists.txt:
FetchContent_Declare(
  h3
  URL      https://github.com/uber/h3/archive/refs/tags/v${H3_CORE_VERSION}.tar.gz
  URL_HASH SHA256=${H3_CORE_SHA256}
)
FetchContent_MakeAvailable(h3)

Deleting the line from CMakeLists.txt made it properly use the
system-installed libh3.

Regina: postgresql-NN-h3 packages are in the repository.

Christoph