What does Homebrew do that OpenSP can compile statically?

[wrobelda]

For the context, I am working on a vcpkg port of OpenSP, which requires static compilation on macOS and Linux. See the discussion here:
microsoft/vcpkg#20347

The problem I am facing is that I cannot compile it statically on Apple Silicon. A simple:

autoreconf --verbose --install --force
./configure --disable-debug --disable-dependency-tracking --enable-http --disable-doc-build --disable-shared --enable-static
make

gives:

/bin/sh ../libtool  --tag=CXX   --mode=link g++  -g -O2   -o onsgmls nsgmls.o SgmlsEventHandler.o RastEventHandler.o StringSet.o nsgmls_inst.o ../lib/libosp.la ../intl/libintl.a -liconv -lpthread
libtool: link: g++ -g -O2 -o onsgmls nsgmls.o SgmlsEventHandler.o RastEventHandler.o StringSet.o nsgmls_inst.o -Wl,-bind_at_load  ../lib/.libs/libosp.a ../intl/libintl.a -liconv -lpthread
ld: warning: ignoring file ../lib/.libs/libosp.a, building for _macOS-arm64_ but attempting to link with file built for _macOS-arm64_
Undefined symbols for architecture arm64:

Notice the puzzling error message: building for macOS-arm64 but attempting to link with file built for macOS-arm64

However, if I brew edit open-sp and add --disable-shared --enable-static to the list of options, it will compile just fine.

Can someone please point me to what does Brew do here that it manages to build it successfully?

Note that I did see the brew's own libtools as dependency and I did try building manually with it being exported per the instructions (export PATH="$(brew --prefix)/opt/libtool/libexec/gnubin:$PATH"), yet it still fails.

I am puzzled and would appreciate any help.

[Bo98]

Hard to tell - might need more of the build log. One suggestion I have is to make sure that GNU Binutils is not in your PATH (it has its own ranlib which conflicts with the macOS one).

Other than that, try take the full build log from your failing output and take the full build log of the Homebrew build (~/Library/Logs/Homebrew/open-sp) and compare the differences.

Homebrew also strips a few compiler flags (indicated by the *.cc logs), but it's unclear yet if that's anything to do with the differences you are seeing.

[wrobelda]

Thanks for your input, much appreciated!

Regarding binutils, I had checked that before.

Comparing the config files – yeah, definitely a good idea. I replicated the environment variables from Brew shell and got my build log as close to brew's as possible. The only thing that didn't work was prepending the PATH with /opt/homebrew/Library/Homebrew/shims/mac/super, which resulted in "C compiler cannot create executables" on my end. However, if I removed that from the Homebrew's env PATH, I was able to replicate the linker issue there, and the log files generated by it were 1:1 identical with my own. So, whatever makes cthe compilation possible is due to Brew's shim-ed compilers or other tools.

[wrobelda]

So it's the 'cmake' shim wrapper specifically that makes the compilation possible. I am now checking all the HOMEBREW_ vars to find the actual reason.

[wrobelda]

OK, it's the /opt/homebrew/lib in HOMEBREW_LIBRARY_PATHS that is added to LDFLAGS by the clang wrapper, most likely caused by liconv or lintl