Static C HDF5 targets aren't static

[blawrence-ont]

Output of brew config

HOMEBREW_VERSION: 4.2.18
ORIGIN: https://github.com/Homebrew/brew
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Curl: 8.4.0 => /usr/bin/curl
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CLT: 15.3.0.0.1.1708646388
Xcode: 15.3
Rosetta 2: false

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Description of issue

When enabling HDF5_USE_STATIC_LIBRARIES in cmake, /opt/homebrew/opt/libaec/lib/libsz.2.dylib is chosen instead of /opt/homebrew/opt/libaec/lib/libsz.a despite asking for static libraries.

Repro case:

CMakeLists.txt:

cmake_minimum_required(VERSION 3.29)
project(test)
set(HDF5_USE_STATIC_LIBRARIES ON)
find_package(HDF5 REQUIRED)
add_executable(test test.c)
target_link_libraries(test HDF5::HDF5)

test.c

#include <hdf5.h>
int main() {
  H5Fopen("", 0, 0);
}

Execution:

% cmake -S . -B build > /dev/null
% cmake --build build > /dev/null
% otool -L build/test | grep libsz

Expected output:

Nothing, since we asked for HDF5_USE_STATIC_LIBRARIES.

Actual output:

        /opt/homebrew/opt/libaec/lib/libsz.2.dylib (compatibility version 2.0.0, current version 2.0.1)

Notes:

The expected output has been the case since at least July 2023 and was working when Homebrew/homebrew-core#159691 (comment) was filed, though I don't know how to narrow down when the behaviour broke after that.

The issue seems to stem from /opt/homebrew/Cellar/hdf5/1.14.3_1/lib/cmake/hdf5/hdf5-targets.cmake which contains this line for the hdf5-static target:

INTERFACE_LINK_LIBRARIES "\$<LINK_ONLY:m>;\$<LINK_ONLY:dl>;/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk/usr/lib/libz.tbd;/opt/homebrew/lib/libsz.dylib;/opt/homebrew/lib/libsz.dylib;\$<\$<NOT:\$<PLATFORM_ID:Windows>>:>;\$<\$<BOOL:OFF>:MPI::MPI_C>;\$<LINK_ONLY:\$<\$<OR:\$<BOOL:OFF>,\$<BOOL:OFF>>:Threads::Threads>>"

Note that libsz.dylib appears twice (why?) and should be libsz.a. I don't know when this file is generated, but if I extract the downloaded Caches/Homebrew/downloads/f5d182938da868e3080c9f4583e29787b35254f3487c8a3c998f1eb31ac25a58--hdf5--1.14.3_1.arm64_sonoma.bottle.tar.gz I can see that it's in there along with MacOSX14.sdk in the path to libz, but shouldn't that be dependent on the SDK installed?

Relevant casks

HDF5