这是我尝试安装 Ruby 2.2 时得到的结果：
$ ruby-install ruby 2.2.10
# ...
>>> Compiling ruby 2.2.10 ...
CC = clang
LD = ld
LDSHARED = clang -dynamic -bundle
CFLAGS = -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wshorten-64-to-32 -Wimplicit-function-declaration -Wdivision-by-zero -Wdeprecated-declarations -Wextra-tokens -pipe
XCFLAGS = -D_FORTIFY_SOURCE=2 -fstack-protector -fno-strict-overflow -fvisibility=hidden -DRUBY_EXPORT -fPIE
CPPFLAGS = -I/opt/X11/include -I/usr/local/opt/openssl@1.1/include -I/usr/local/opt/readline/include -I/usr/local/opt/libyaml/include -I/usr/local/opt/gdbm/include -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -D_DARWIN_UNLIMITED_SELECT -D_REENTRANT -I. -I.ext/include/x86_64-darwin19 -I./include -I.
DLDFLAGS = -Wl,-undefined,dynamic_lookup -Wl,-multiply_defined,suppress -L/usr/local/opt/openssl@1.1/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/gdbm/lib -fstack-protector -Wl,-u,_objc_msgSend …我继承了一个遗留代码库，需要使用 RVM 安装 Ruby 2.0.0。我使用的是 Mac OS X Catalina，Ruby 2.0.0 的安装程序根本不起作用。
以下是我的安装尝试，从 RVM 本身的安装一直到尝试安装 Ruby 2.0.0。
nbyrd$ \curl -sSL https://get.rvm.io | bash -s stable
Downloading https://github.com/rvm/rvm/archive/1.29.10.tar.gz
Downloading https://github.com/rvm/rvm/releases/download/1.29.10/1.29.10.tar.gz.asc
gpg: Signature made Wed Mar 25 14:58:42 2020 PDT
gpg: using RSA key 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
gpg: Good signature from "Piotr Kuczynski <piotr.kuczynski@gmail.com>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: 7D2B AF1C F37B 13E2 …