home-brew install fails on High Sierra

[cabo]

Lots of undefined references in building some of the examples:

.../Library/Homebrew/shims/mac/super/clang  -std=c99 -O3 -flto -Wall -pedantic -DNDEBUG -Wl,-search_paths_first -Wl,-headerpad_max_install_names -flto CMakeFiles/readfile.dir/readfile.c.o  -o readfile ../src/libcbor.a 
undef: _cbor_build_bool
undef: _cbor_build_uint8
undef: _cbor_build_string
undef: _cbor_move
undef: _cbor_new_definite_map
undef: _cbor_map_add
undef: _cbor_serialize_alloc
undef: _cbor_decref
Undefined symbols for architecture x86_64:
  "_cbor_build_bool", referenced from:
      _main in lto.o
  "_cbor_build_uint8", referenced from:
      _main in lto.o
  "_cbor_build_string", referenced from:
      _main in lto.o
  "_cbor_move", referenced from:
      _main in lto.o
  "_cbor_new_definite_map", referenced from:
      _main in lto.o
  "_cbor_map_add", referenced from:
      _main in lto.o
  "_cbor_serialize_alloc", referenced from:
      _main in lto.o
  "_cbor_decref", referenced from:
      _main in lto.o
ld: symbol(s) not found for architecture x86_64
undef: _cbor_new_definite_array
undef: _cbor_get_uint8
undef: _cbor_build_uint8
undef: _cbor_array_push
undef: _cbor_move
undef: _cbor_array_handle
undef: _cbor_array_size
undef: _cbor_describe
Undefined symbols for architecture x86_64:
  "_cbor_new_definite_array", referenced from:
      _main in lto.o
  "_cbor_get_uint8", referenced from:
      _comparUint in lto.o
  "_cbor_build_uint8", referenced from:
      _main in lto.o
  "_cbor_array_push", referenced from:
      _main in lto.o
  "_cbor_move", referenced from:
      _main in lto.o
  "_cbor_array_handle", referenced from:
      _main in lto.o
  "_cbor_array_size", referenced from:
      _main in lto.o
  "_cbor_describe", referenced from:
      _main in lto.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [examples/create_items] Error 1
make[1]: *** [examples/CMakeFiles/create_items.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
undef: _cbor_empty_callbacks
undef: _cbor_stream_decode
Undefined symbols for architecture x86_64:
  "_cbor_empty_callbacks", referenced from:
      _main in lto.o
  "_cbor_stream_decode", referenced from:
      _main in lto.o
ld: symbol(s) not found for architecture x86_64
make[2]: *** [examples/sort] Error 1
make[1]: *** [examples/CMakeFiles/sort.dir/all] Error 2
undef: _cbor_load
undef: _cbor_describe
undef: _cbor_decref
Undefined symbols for architecture x86_64:
  "_cbor_load", referenced from:
      _main in lto.o
  "_cbor_describe", referenced from:
      _main in lto.o
  "_cbor_decref", referenced from:
      _main in lto.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [examples/streaming_parser] Error 1
make[1]: *** [examples/CMakeFiles/streaming_parser.dir/all] Error 2
make[2]: *** [examples/readfile] Error 1
make[1]: *** [examples/CMakeFiles/readfile.dir/all] Error 2
[100%] Built target hello
cd .../tmp/libcbor-20190119-19049-1m752yw/libcbor-0.5.0/build/src && .../Cellar/cmake/3.13.3/bin/cmake -E cmake_symlink_library libcbor.0.0.0.dylib libcbor.0.dylib libcbor.dylib
[100%] Built target cbor_shared
make: *** [all] Error 2

[PJK]

I pushed some minor fixes to https://github.com/PJK/homebrew-libcbor to make the formula compatible with the latest homebrew, but I doubt that solves the root cause of your issue.

Could you please try brew install -v libcbor again with an up-to-date homebrew (homebrew update)? For reference, I get https://gist.github.com/PJK/c3c9bcaf327c402d456c761bd674a0a5 on a 10.13 mac.

[cabo]

Maybe I don't understand Mac builds well enough, but the surprising part is that src/libcbor.a consists of .o files of the form:

arrays.c.o:            LLVM bitcode, wrapper x86_64
builder_callbacks.c.o: LLVM bitcode, wrapper x86_64
bytestrings.c.o:       LLVM bitcode, wrapper x86_64
callbacks.c.o:         LLVM bitcode, wrapper x86_64
cbor.c.o:              LLVM bitcode, wrapper x86_64
common.c.o:            LLVM bitcode, wrapper x86_64
encoders.c.o:          LLVM bitcode, wrapper x86_64
encoding.c.o:          LLVM bitcode, wrapper x86_64
floats_ctrls.c.o:      LLVM bitcode, wrapper x86_64
ints.c.o:              LLVM bitcode, wrapper x86_64
loaders.c.o:           LLVM bitcode, wrapper x86_64
maps.c.o:              LLVM bitcode, wrapper x86_64
memory_utils.c.o:      LLVM bitcode, wrapper x86_64
serialization.c.o:     LLVM bitcode, wrapper x86_64
stack.c.o:             LLVM bitcode, wrapper x86_64
streaming.c.o:         LLVM bitcode, wrapper x86_64
strings.c.o:           LLVM bitcode, wrapper x86_64
tags.c.o:              LLVM bitcode, wrapper x86_64
unicode.c.o:           LLVM bitcode, wrapper x86_64

nm -p is helpless.

[PJK]

I know next to nothing about OSX details, but I believe the reason this doesn't emit plain object files (if that is what you're alluding) is that LTO is enabled for release builds which triggers this behavior in clang (https://github.com/mull-project/mull/blob/master/Docs/HowToGetLLVMBitcode.md).

[PJK]

If the above is the real cause, it will be solved by Homebrew/homebrew-core#50588