安装并加载软件包gdtools

Question

从CRAN信息库安装软件包'gdtools'似乎一切都很好，但是，在加载库时，出现以下错误：

Error: package or namespace load failed for ‘gdtools’ in dyn.load(file, DLLpath = DLLpath, ...):
 unable to load shared object '/Library/Frameworks/R.framework/Versions/3.5/Resources/library/gdtools/libs/gdtools.so':
 dlopen(/Library/Frameworks/R.framework/Versions/3.5/Resources/library/gdtools/libs/gdtools.so, 6): Library not loaded: /opt/X11/lib/libcairo.2.dylib
Referenced from: /Library/Frameworks/R.framework/Versions/3.5/Resources/library/gdtools/libs/gdtools.so
Reason: image not found

关于如何解决问题的任何想法。

提前感谢您的时间。