安装git2r失败，因为'Library not loaded：libz.1.dylib'

Question

我正在尝试在macOS sierra的新R 3.4安装中安装软件包devtools。 git2r安装失败并显示以下消息（反过来devtools无法安装）。

Error: package or namespace load failed for ‘git2r’ in dyn.load(file, DLLpath = DLLpath, ...):
 unable to load shared object '/Users/xxx/Library/R/3.4/library/git2r/libs/git2r.so':

 dlopen(/Users/xxx/Library/R/3.4/library/git2r/libs/git2r.so, 6): Library not loaded: libz.1.dylib
 Referenced from: /Users/xxx/Library/R/3.4/library/git2r/libs/git2r.so
 Reason: image not found
 Error: loading failed

brew医生很干净，这里是sessionInfo（）的结果。

R version 3.4.0 (2017-04-21)
Platform: x86_64-apple-darwin16.5.0 (64-bit)
Running under: macOS Sierra 10.12.5

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libLAPACK.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] compiler_3.4.0