在R中安装ggmap出现依赖错误：png包加载失败

尝试的安装代码 #

install.packages("png")
install.packages("RgoogleMaps")
install.packages("ggmap")
library(ggmap)

报错信息 #

installing to /usr/local/Cellar/r/4.2.2/lib/R/library/00LOCK-png/00new/png/libs
** R
** inst
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
** building package indices
** testing if installed package can be loaded from temporary location
Error: package or namespace load failed for ‘png’ in dyn.load(file, DLLpath = DLLpath, ...):
 unable to load shared object '/usr/local/Cellar/r/4.2.2/lib/R/library/00LOCK-png/00new/png/libs/png.so':
  dlopen(/usr/local/Cellar/r/4.2.2/lib/R/library/00LOCK-png/00new/png/libs/png.so, 6): Library not loaded: @rpath/libz.1.dylib
  Referenced from: /usr/local/Cellar/r/4.2.2/lib/R/library/00LOCK-png/00new/png/libs/png.so
  Reason: image not found
Error: loading failed
Execution halted
ERROR: loading failed
* removing ‘/usr/local/Cellar/r/4.2.2/lib/R/library/png’
Warning in install.packages :
  installation of package ‘png’ had non-zero exit status
ERROR: dependency ‘png’ is not available for package ‘RgoogleMaps’
* removing ‘/usr/local/Cellar/r/4.2.2/lib/R/library/RgoogleMaps’
Warning in install.packages :
  installation of package ‘RgoogleMaps’ had non-zero exit status
ERROR: dependencies ‘RgoogleMaps’, ‘png’ are not available for package ‘ggmap’
* removing ‘/usr/local/Cellar/r/4.2.2/lib/R/library/ggmap’
Warning in install.packages :
  installation of package ‘ggmap’ had non-zero exit status

The downloaded source packages are in
    ‘/private/var/folders/fd/7vyffy191_l3j6fhyqbvsn0r0000gn/T/RtmptKSXHF/downloaded_packages’
Updating HTML index of packages in '.Library'
Making 'packages.html' ... done
Error in library(ggmap) : there is no package called ‘ggmap’

解决方案 #

问题根源是系统缺少zlib库，或R无法正确定位该库路径。按以下步骤操作：

1. 通过Homebrew安装zlib（若未安装）：

   brew install zlib
   

2. 在R中设置环境变量，让png包安装时能找到zlib：

   Sys.setenv(ZLIB_LIBS="-L/usr/local/opt/zlib/lib")
   Sys.setenv(ZLIB_CFLAGS="-I/usr/local/opt/zlib/include")
   install.packages("png", type = "source")
   

3. 成功安装png包后，继续安装剩余依赖和ggmap：

   install.packages("RgoogleMaps")
   install.packages("ggmap")
   library(ggmap)
   

若上述步骤无效，建议重新通过Homebrew安装R，确保系统依赖正确链接：

brew reinstall r

内容的提问来源于stack exchange，提问作者Manuel Ravasqueira