Here's my output of error messages when downlading blotter.
Downloading GitHub repo braverock/blotter@master
from URL https://api.github.com/repos/braverock/blotter/zipball/master
WARNING: Rtools is required to build R packages, but no version of Rtools compatible with R 3.5.1 was found. (Only the following incompatible version(s) of Rtools were found:3.4,3.5)
Please download and install the appropriate version of Rtools from http://cran.r-project.org/bin/windows/Rtools/.
"C:/Users/JWILLI~1/DOWNLO~1/R/R-35~1.1/bin/x64/R" --no-site-file --no-environ
--no-save --no-restore --quiet CMD INSTALL
- installing source package 'blotter' ...
*** arch - i386
Warning in system(cmd) : 'make' not found
ERROR: compilation failed for package 'blotter'
- removing 'C:/Users/jwilliams/Downloads/R/R-3.5.1/library/blotter'
In R CMD INSTALL
Installation failed: Command failed (1)
I'm focusing on the blotter package first because it is a dependency for quantstrat.