安装devtools的时候,需要安装testthat和pkgload。但是安装testthat时候说需要安装pkgload, 然后安装pkgload又说需要安装testthat,陷入死循环了,请问该怎么办呢。
** testing if installed package can be loaded from temporary location
Error: package or namespace load failed for ‘pkgload’:
.onLoad failed in loadNamespace() for 'pkgload', details:
call: NULL
error: package ‘testthat’ was installed by an R version with different internals; it needs to be reinstalled for use with this R version