Crystal: Can not install crystal at macos through brew install

[garyhe0780]

when I ran brew install crystal , I got the following error:
```bash
make
crystal
release=true
FLAGS=--no-debug
CRYSTAL_CONFIG_LIBRARY_PATH=

Using /usr/local/opt/llvm/bin/llvm-config [version=10.0.1]
CRYSTAL_CONFIG_LIBRARY_PATH="" CRYSTAL_CONFIG_BUILD_COMMIT="" SOURCE_DATE_EPOCH="1592582883" ./bin/crystal build --no-debug --release -o .build/crystal src/compiler/crystal.cr -D without_openssl -D without_zlib
ld: library not found for -llibxml2.tbd (this usually means you need to install the development package for liblibxml2.tbd)
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Error: execution of command failed with code: 1: clang "${@}" -o '/private/tmp/crystal-20200919-29356-18f2s4n/crystal-0.35.1/.build/crystal' -rdynamic /private/tmp/crystal-20200919-29356-18f2s4n/crystal-0.35.1/src/llvm/ext/llvm_ext.o"/usr/local/opt/llvm/bin/llvm-config" --libs --system-libs --ldflags 2> /dev/null-lstdc++ -lpcre -lgc -lpthread /private/tmp/crystal-20200919-29356-18f2s4n/crystal-0.35.1/src/ext/libcrystal.a -levent -liconv -ldl -L/private/tmp/crystal-20200919-29356-18f2s4n/crystal-0.35.1/boot/embedded/lib -L/private/tmp/crystal-20200919-29356-18f2s4n/crystal-0.35.1/boot/embedded/lib
make: * [.build/crystal] Error 1
`

[Blacksmoke16]

Looks like you're missing libxml2. What happens if you do like:

brew install libxml2
brew install crystal

[Sija]

@garyhe0780 See https://github.com/ziglang/zig/issues/6087#issuecomment-675746460

[bcardiff]

Ref: https://github.com/Homebrew/homebrew-core/pull/61005

As a temporal workaround you can either:

A. install llvm from 6616d50fb0b24dbe30f5e975210bdad63257f517 brew version you will have 10.0.0 which works.

B. Use the darwin .tar.gz from github releases.

[garyhe0780]

Looks like you're missing libxml2. What happens if you do like:

brew install libxml2
brew install crystal

had libxml2 installed, still the same

[garyhe0780]

Ref: Homebrew/homebrew-core#61005

As a temporal workaround you can either:

A. install llvm from 6616d50fb0b24dbe30f5e975210bdad63257f517 brew version you will have 10.0.0 which works.

B. Use the darwin .tar.gz from github releases.

You're right, I tried brew reinstall --build-from-source Formula/llvm and try brew install crystal, It worked, thanks very much, you really saved my day.