我使用的是Mac catalina系统，安装R3.6.3，在安装gEcon时出现如下错误。
诚心请问各位大佬，应该如何解决？


> install.packages("http://gecon.r-forge.r-project.org/files/gEcon_1.2.0.tar.gz", repos = NULL)
trying URL 'http://gecon.r-forge.r-project.org/files/gEcon_1.2.0.tar.gz'
Content type 'application/x-gzip' length 375927 bytes (367 KB)
==================================================
downloaded 367 KB

ERROR: dependencies ‘nleqslv’, ‘Rcpp’ are not available for package ‘gEcon’
* removing ‘/Library/Frameworks/R.framework/Versions/3.6/Resources/library/gEcon’
Warning message:
In install.packages("http://gecon.r-forge.r-project.org/files/gEcon_1.2.0.tar.gz",  :
  installation of package ‘/var/folders/h1/h3k8tn011fggh7tw0jw60v1c0000gn/T//RtmpPI4VEp/downloaded_packages/gEcon_1.2.0.tar.gz’ had non-zero exit status
>