安装corsstools-NG的问题

我下载好后 ./ct-ng build
出现了这个问题

[INFO ]  Performing some trivial sanity checks
[ERROR]  Your file system in '/mnt/hgfs/shareCD/esp/crosstool-NG/.build' is *not* case-sensitive!
[ERROR]   
[ERROR]  >>
[ERROR]  >>  Build failed in step '(top-level)'
[ERROR]  >>
[ERROR]  >>  Error happened in: CT_Abort[scripts/functions@331]
[ERROR]  >>        called from: CT_TestAndAbort[scripts/functions@351]
[ERROR]  >>        called from: main[scripts/crosstool-NG.sh@93]
[ERROR]  >>
[ERROR]  >>  For more info on this error, look at the file: 'build.log'
[ERROR]  >>  There is a list of known issues, some with workarounds, in:
[ERROR]  >>      '/home/tjw/workspace/esp/crosstool-NG/docs/B - Known issues.txt'
[ERROR]   
[ERROR]  (elapsed: 26281751:10.23)
[00:00] / ct-ng:152: recipe for target 'build' failed
make: *** [build] Error 1

求问这是什么意思,我该怎么做