'pthread.h' file not found

重い腰を上げてmacruby 3をインストール

rbenvの更新

$ brew upgrade ruby-build

rbenvでruby 3をインストール

$ rbenv install 3.0.0
Downloading openssl-1.1.1i.tar.gz...
-> https://dqw8nmjcqpjn7.cloudfront.net/e8be6a35fe41d10603c3cc635e93289ed00bf34b79671a3a4de64fcee00d5242
Installing openssl-1.1.1i...

BUILD FAILED (macOS 11.2.1 using ruby-build 20210119)

Inspect or clean up the working tree at /var/folders/4t/bm7k_g7d37v5n9vxv6lfzjnh0000gn/T/ruby-build.20210227222639.27074.JMBx8l
Results logged to /var/folders/4t/bm7k_g7d37v5n9vxv6lfzjnh0000gn/T/ruby-build.20210227222639.27074.log

Last 10 log lines:
clang  -I. -Iinclude -fPIC -arch x86_64 -O3 -Wall -DL_ENDIAN -DOPENSSL_PIC -DOPENSSL_CPUID_OBJ -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DKECCAK1600_ASM -DRC4_ASM -DMD5_ASM -DAESNI_ASM -DVPAES_ASM -DGHASH_ASM -DECP_NISTZ256_ASM -DX25519_ASM -DPOLY1305_ASM -DOPENSSLDIR="\"/Users/nyan/.rbenv/versions/3.0.0/openssl/ssl\"" -DENGINESDIR="\"/Users/nyan/.rbenv/versions/3.0.0/openssl/lib/engines-1.1\"" -D_REENTRANT -DZLIB -DZLIB_SHARED -DNDEBUG -I/Users/nyan/.rbenv/versions/3.0.0/include  -MMD -MF crypto/asn1/x_val.d.tmp -MT crypto/asn1/x_val.o -c -o crypto/asn1/x_val.o crypto/asn1/x_val.c
clang  -I. -Iinclude -fPIC -arch x86_64 -O3 -Wall -DL_ENDIAN -DOPENSSL_PIC -DOPENSSL_CPUID_OBJ -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DKECCAK1600_ASM -DRC4_ASM -DMD5_ASM -DAESNI_ASM -DVPAES_ASM -DGHASH_ASM -DECP_NISTZ256_ASM -DX25519_ASM -DPOLY1305_ASM -DOPENSSLDIR="\"/Users/nyan/.rbenv/versions/3.0.0/openssl/ssl\"" -DENGINESDIR="\"/Users/nyan/.rbenv/versions/3.0.0/openssl/lib/engines-1.1\"" -D_REENTRANT -DZLIB -DZLIB_SHARED -DNDEBUG -I/Users/nyan/.rbenv/versions/3.0.0/include  -MMD -MF crypto/async/arch/async_null.d.tmp -MT crypto/async/arch/async_null.o -c -o crypto/async/arch/async_null.o crypto/async/arch/async_null.c
In file included from crypto/async/arch/async_null.c:11:
In file included from crypto/async/arch/../async_local.h:24:
include/openssl/crypto.h:415:13: fatal error: 'pthread.h' file not found
#   include <pthread.h>
            ^~~~~~~~~~~
1 error generated.
make[1]: *** [crypto/async/arch/async_null.o] Error 1
make: *** [all] Error 2

おや?まあ、どうせまたapple clang絡みでしょ・・・、というわけで脳死brewgccをインストール

$ brew install gcc
$ rbenv install 3.0.0                                                                                      [feature/update_ruby]
Downloading openssl-1.1.1i.tar.gz...
-> https://dqw8nmjcqpjn7.cloudfront.net/e8be6a35fe41d10603c3cc635e93289ed00bf34b79671a3a4de64fcee00d5242
Installing openssl-1.1.1i...
Installed openssl-1.1.1i to /Users/nyan/.rbenv/versions/3.0.0

Downloading ruby-3.0.0.tar.gz...
-> https://cache.ruby-lang.org/pub/ruby/3.0/ruby-3.0.0.tar.gz
Installing ruby-3.0.0...
ruby-build: using readline from homebrew
Installed ruby-3.0.0 to /Users/nyan/.rbenv/versions/3.0.0

上手く行ったっぽい