The following issue was reported to me. I've reproduced it on Cygwin 2 and 3, on a couple of machines. When using paths beginning 'C:/' the 'access' function claims that directories are readable when they are not. The same problem does not arise when starting the same directory name with '/cygdrive/c/'. I attach a minimal example program showing the problem. When I run it it returns that both ways of naming 'System Volume Information' exist, but that 'C:/System Volume Information' can be Read (which is wrong), while '/cygdrive/c/System Volume Information' can't be Read. #include #include int main(void) { int ok1 = access("C:/System Volume Information/", F_OK); int ok2 = access("/cygdrive/c/System Volume Information", F_OK); int read1 = access("C:/System Volume Information/", R_OK); int read2 = access("/cygdrive/c/System Volume Information", R_OK); printf("%d,%d\n%d,%d\n", ok1, read1, ok2, read2); } // Prints 0,0 0,-1