我试图在我的RStudio版本“Spotted Wakerobin”中安装来自CRAN的减价包，该版本使用R版本4.2.1，但我收到以下错误：

C:\rtools42\usr\bin\gcc  -I"C:/PROGRA~1/R/R-42~1.1/include" -DNDEBUG     -I"C:/rtools42/x86_64-w64-mingw32.static.posix/include"     -O2 -Wall  -std=gnu99 -mfpmath=sse -msse2 -mstackrealign  -c Rbase64.c -o Rbase64.o
/bin/sh: line 1: C:rtools42usrbingcc: command not found
make: *** [C:/PROGRA~1/R/R-42~1.1/etc/x64/Makeconf:253: Rbase64.o] Error 127
ERROR: compilation failed for package 'markdown'
* removing 'C:/Program Files/RPackages/markdown'
Warning in install.packages :
  installation of package ‘markdown’ had non-zero exit status

看起来它找不到应该在那里的东西，这可能与gcc有关。这是我的gcc版本信息：

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=c:/rtools42/x86_64-w64-mingw32.static.posix/bin/../libexec/gcc/x86_64-w64-mingw32.static.posix/10.4.0/lto-wrapper.exe
Target: x86_64-w64-mingw32.static.posix
Configured with: /root/mxe/tmp-gcc-host-x86_64-w64-mingw32.static.posix/gcc-10.4.0/configure --host=x86_64-w64-mingw32.static.posix --target=x86_64-w64-mingw32.static.posix --build=x86_64-pc-linux-gnu --prefix=/usr/lib/mxe/usr/x86_64-w64-mingw32.static.posix --with-native-system-header-dir=/usr/lib/mxe/usr/x86_64-w64-mingw32.static.posix/include --enable-languages=c,c++,objc,fortran --enable-version-specific-runtime-libs --with-gcc --with-gnu-ld --with-gnu-as --disable-nls --without-libiconv-prefix --disable-shared --disable-multilib --without-x --disable-win32-registry --enable-threads=posix --enable-libgomp --with-gmp=/usr/lib/mxe/usr/x86_64-w64-mingw32.static.posix --with-isl=/usr/lib/mxe/usr/x86_64-w64-mingw32.static.posix --with-mpc=/usr/lib/mxe/usr/x86_64-w64-mingw32.static.posix --with-mpfr=/usr/lib/mxe/usr/x86_64-w64-mingw32.static.posix --enable-libstdcxx-time target_configargs=XCFLAGS=-Wno-format
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.4.0 (GCC)

我已经设置了以下环境变量：
| 变量|数值|
| - -|- -|
| 路径|C：\程序文件\R\R-4.0.5\bin; C：\rtools42\usr\bin;|
| BINPREF（二进制优先级）|C：\rtools42\x86_64-w 64-mingw32.static.posix\bin\中的文件夹中的文件夹|
| R_起始位置|C：\程式档\R\R-4.0.5\程式库\基底\R\R设定档|
| R_库_用户|C：\程序文件\R程序包|
| R_用户|C：\程序文件\R\R-4.0.5|
| RTOOLS 42_主页|C：\r工具42|
我在想下一步该怎么做？