mac os x使用brew重新安装php55，总是提示bzip2缺少，需要重装，但系统中确实已经有了bzip2.
Last login: Sun May 17 12:48:12 on ttys001
bogon:~ ksoul$ brew list
aspell flex gmp libffi re2c
autoconf freetds icu4c libpng tidy-html5
bzip2 freetype imap-uw nginx unixodbc
curl gettext jpeg openssl wget
enchant glib lbzip2 pcre zlib
bogon:~ ksoul$ whereis bzip2
/usr/bin/bzip2
bogon:~ ksoul$ brew install php55 --with-cgi --with-debug --withgmp --with-imap --with-tidy
==> Installing php55 from josegonzalez/homebrew-php
==> Downloading https://www.php.net/get/php-5.5.25.tar.bz2/from/this/mirror
Already downloaded: /Library/Caches/Homebrew/php55-5.5.25
Warning: Backing up all known pear.conf and .pearrc files
Warning: If you have a pre-existing pear install outside
of homebrew-php, or you are using a non-standard
pear.conf location, installation may fail.
==> ./configure --prefix=/usr/local/Cellar/php55/5.5.25 --localstatedir=/usr/loc
checking for gzgets in -lz... yes
checking whether to enable bc style precision math functions... yes
checking for BZip2 support... yes
checking for BZip2 in default path... not found
configure: error: Please reinstall the BZip2 distribution
READ THIS: https://git.io/brew-troubleshooting
If reporting this issue please do so at (not Homebrew/homebrew):
https://github.com/josegonzalez/homebrew-php/issues
bogon:~ ksoul$
遇到同样的问题，求解答
试试：xcode-select --install
很可能没安装完全，开个VPN下载试试。