问题
R has been installing packages just fine, but suddenly – I can't think of anything relevant that I modified or uninstalled –
it can't find gcc when I run R CMD check in the command prompt, or devtools::check() in the R console; it delivers the following error:
* installing *source* package 'PkgName' ...
** libs
C:/MinGW/bin/gcc -I"C:/PROGRA~1/R/R-34~1.2/include" -DNDEBUG -I"d:/Compiler/gcc-4.9.3/local330/include" -O3 -Wall -std=gnu99 -mtune=core2 -c PkgName-init.c -o PkgName-init.o
C:/MinGW/bin/gcc: not found
I want R to find gcc in C:\Rtools-3.4\mingw_32\bin, which is the location specified in the system PATH; strsplit(Sys.getenv('PATH'), ';') gives
[...]
[4] "c:\\Rtools-3.4\\bin"
[5] "c:\\Rtools-3.4\\mingw_32\\bin"
[7] "C:\\Program Files\\R\\R-3.4.2\\bin\\i386"
[8] "C:\\Program Files\\R\\R-3.4.2\\bin"
[9] "C:\\Program Files\\MiKTeX 2.9\\miktex\\bin\\x64\\"
[...]
How can I tell R not to look in the non-existent directory C:\MinGW, and instead to follow the PATH?
I don't want to install a second copy of MinGW there, as this causes other issues.
回答1:
R uses a BINPREF variable to locate executables:
the location of the gcc executable is given by CC = $(BINPREF)gcc $(M_ARCH)
In my case, BINPREF was being set by C:/Users/MYUSERNAME/Documents/.R/Makevars. Deleting the contents of this file removed the incorrect location.
It is also worth checking the file $RPATH/etc/i386/Makeconf, which will be re-created with each new installation of R. Note the line
BINPREF ?= c:/Rtools/mingw_32/bin/, which (via the ?= operator) will set the value of BINPREF if it is not already set, as it was in the Makevars file mentioned above.
来源：https://stackoverflow.com/questions/47076620/r-cmd-check-not-looking-for-gcc-in-rtools-directory