gcc 4.5.1 installation error on ubuntu 11.04

[ravish112]

Hi,

I was trying to install gcc 4.5.1 on ubuntu 11.04 I got following error:-

under /usr/bin/gcc version is 4.5.2

/usr/include/unistd.h:275:21: error: two or more data types in declaration specifiers

in line #275 of /usr/include/unistd.h

we have

#if defined __USE_BSD || defined __USE_XOPEN
# ifndef __socklen_t_defined
typedef __socklen_t socklen_t;
# define __socklen_t_defined
# endif
#endif

Could you please help me in this scenario