Factor out the code to find gcc, and add a command-line option to override the default executable name. This should help cross-compilation by allowing a cross-gcc to be specified from the configuration file instead of only through the CC environment variable.

module bug77;
import tango.stdc.string;
void main()
{
    size_t len;
    void func2()
    {
        char* prefix = "";

        void func()
        {
        len = strlen(prefix);
        assert(len == 0);
        }

        func();
    }
    func2();
}