尝试安装XML时出现以下错误：
** testing if installed package can be loaded
Error : .onLoad failed in loadNamespace() for 'XML', details:
call: dyn.load(file, DLLpath = DLLpath, ...)
error: unable to load shared object '/usr/local/lib/R/3.3/site-library/XML/libs/XML.so':
dlopen(/usr/local/lib/R/3.3/site-library/XML/libs/XML.so, 6): Library not loaded: @rpath/libz.1.dylib
Referenced from: /usr/local/lib/R/3.3/site-library/XML/libs/XML.so
Reason: image not found
Error: loading failed
Execution halted
ERROR: loading failed
* removing ‘/usr/local/lib/R/3.3/site-library/XML’
我阅读了指南here（适用于xml2而不是XML），它有同样的问题，但解决方案对我不起作用。我下载了软件包，并尝试使用以下命令安装它：
R CMD INSTALL --configure-vars='INCLUDE_DIR=/usr/include/ LIB_DIR=/usr/lib' .
但我仍然得到同样的错误。
由于我愚蠢地安装了anaconda和homebrew，我总共安装了3个版本的libxml：
Ians-MacBook-Pro Thu Jun 23 11:54 10.10 $which xml2-config
xml2-config is /Users/ifiddes/anaconda/bin/xml2-config
xml2-config is /usr/local/bin/xml2-config
xml2-config is /usr/bin/xml2-config
我尝试使用所有3个版本的libxml2运行上面的install命令。所有编译，但以相同的方式在加载步骤失败。
我似乎在libz.1.dylib
/usr/lib的副本
Ians-MacBook-Pro Thu Jun 23 14:21 ~ $ls /usr/lib/libz*dylib
-rwxr-xr-x 1 root wheel 174K May 4 23:15 /usr/lib/libz.1.dylib
lrwxr-xr-x 1 root wheel 12B Jun 23 11:27 /usr/lib/libz.dylib -> libz.1.dylib
lrwxr-xr-x 1 root wheel 12B Jun 23 11:27 /usr/lib/libz.1.2.5.dylib -> libz.1.dylib
lrwxr-xr-x 1 root wheel 12B Jun 23 11:27 /usr/lib/libz.1.1.3.dylib -> libz.1.dylib
以下是Sys.getenv()的输出：
> Sys.getenv()
__CF_USER_TEXT_ENCODING
0x1F5:0x0:0x0
Apple_PubSub_Socket_Render
/private/tmp/com.apple.launchd.hmbX5Ty62C/Render
CLICOLOR 1
COLORFGBG 7;0
COLUMNS 100
DISPLAY /private/tmp/com.apple.launchd.v48pxvb3MZ/org.macosforge.xquartz:0
DYLD_FALLBACK_LIBRARY_PATH
/usr/local/Cellar/r/3.3.1/R.framework/Resources/lib:/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/server
EDITOR vi
HISTFILE /Users/ifiddes/.eternal_bash_history
HISTFILESIZE
HISTSIZE
HISTTIMEFORMAT [%D %T]
HOME /Users/ifiddes
ITERM_PROFILE Default
ITERM_SESSION_ID w3t0p1:E8AA203F-887F-457B-94AF-10956110B2BD
LANG en_US.UTF-8
LINES 25
LN_S ln -s
LOGNAME ifiddes
LSCOLORS ExFxBxDxCxegedabagacad
MAKE make
PAGER /usr/bin/less
PATH /Users/ifiddes/perl5/bin:/Users/ifiddes/anaconda/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin
PERL_LOCAL_LIB_ROOT /Users/ifiddes/perl5
PERL_MB_OPT --install_base "/Users/ifiddes/perl5"
PERL_MM_OPT INSTALL_BASE=/Users/ifiddes/perl5
PERL5LIB /Users/ifiddes/perl5/lib/perl5
PWD /Users/ifiddes
PYTHONSTARTUP /Users/ifiddes/.pythonstartup
R_ARCH
R_BROWSER /usr/bin/open
R_BZIPCMD /usr/bin/bzip2
R_DOC_DIR /usr/local/Cellar/r/3.3.1/R.framework/Resources/doc
R_GZIPCMD /usr/bin/gzip
R_HOME /usr/local/Cellar/r/3.3.1/R.framework/Resources
R_INCLUDE_DIR /usr/local/Cellar/r/3.3.1/R.framework/Resources/include
R_LIBS_SITE
R_LIBS_USER ~/Library/R/3.3/library
R_PAPERSIZE a4
R_PDFVIEWER /usr/bin/open
R_PLATFORM x86_64-apple-darwin15.5.0
R_PRINTCMD lpr
R_RD4PDF times,inconsolata,hyper
R_SESSION_TMPDIR /var/folders/mb/7j7j53614qb36bp2qwfcr8dr0000gn/T//RtmpH5QKZH
R_SHARE_DIR /usr/local/Cellar/r/3.3.1/R.framework/Resources/share
R_SYSTEM_ABI osx,gcc,gxx,gfortran,?
R_TEXI2DVICMD /usr/local/opt/texinfo/bin/texi2dvi
R_UNZIPCMD /usr/bin/unzip
R_ZIPCMD /usr/bin/zip
SED /usr/local/Library/ENV/4.3/sed
SHELL /bin/bash
SHLVL 1
SSH_AUTH_SOCK /private/tmp/com.apple.launchd.UH9wqQZqMU/Listeners
TAR /usr/bin/tar
TERM xterm-256color
TERM_PROGRAM iTerm.app
TERM_PROGRAM_VERSION 3.0.0
TERM_SESSION_ID w3t0p1:E8AA203F-887F-457B-94AF-10956110B2BD
TMPDIR /var/folders/mb/7j7j53614qb36bp2qwfcr8dr0000gn/T/
USER ifiddes
XPC_FLAGS 0x0
XPC_SERVICE_NAME 0