gcc 4.9.1有什麼問題？

Question

在最新的gcc 4.9.1包，在./configure之後我跑令，並將其與錯誤消息失敗：

checking for x86_64-unknown-linux-gnu-gcc... /root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/xgcc -B/root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/ -B/usr/local/x86_64-unknown-linux-gnu/bin/ -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem /usr/local/x86_64-unknown-linux-gnu/include -isystem /usr/local/x86_64-unknown-linux-gnu/sys-include 
checking for suffix of object files... configure: error: in `/root/tar/gcc-4.9.1/x86_64-unknown-linux-gnu/libgcc': 
configure: error: cannot compute suffix of object files: cannot compile 
See `config.log' for more details. 

我檢查的config.log在x86_64的未知-Linux的GNU/libgcc的/，它說，

configure:3389: /root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/xgcc -B/root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/ -B/usr/local/x86_64-unknown-linux-gnu/bin/ -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem /usr/local/x86_64-unknown-linux-gnu/include -isystem /usr/local/x86_64-unknown-linux-gnu/sys-include -o conftest -g -O2 conftest.c >&5 
/root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/cc1: error while loading shared libraries: libmpc.so.2: cannot open shared object file: No such file or directory 
configure:3392: $? = 1 
configure:3580: checking for suffix of object files 
configure:3602: /root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/xgcc -B/root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/ -B/usr/local/x86_64-unknown-linux-gnu/bin/ -B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem /usr/local/x86_64-unknown-linux-gnu/include -isystem /usr/local/x86_64-unknown-linux-gnu/sys-include -c -g -O2 conftest.c >&5 
/root/tar/gcc-4.9.1/host-x86_64-unknown-linux-gnu/gcc/cc1: error while loading shared libraries: libmpc.so.2: cannot open shared object file: No such file or directory 
configure:3606: $? = 1 
configure: failed program was: 

但很明顯，我有libmpc.so.2在/ usr/local/lib中。怎麼了？？

Answer 1

看起來問題是由於缺省路徑/ usr/local/lib未包含在$ LD_LIBRARY_PATH環境變量中。對不起，這個愚蠢的問題...