Running g++ with an empty (or partially filled) card reader will throw a No Disk error:
There is no disk in the drive. Please insert a disk into drive \Device\Harddisk5\DR17.
Connecting the hub to other USB ports returns the same error (different DR). However, the compiler will still compile.
OS: Windows 7 Home Premium + SP1
GCC Version: 4.8.1
Binutils Version: 2.23.2
Build Env: cmd.exe/tcc.exe