On 18 May 2011 07:40, Klaus Rudolph wrote: > Hi all, > > after I update my ubuntu system to 11.04 I got some strange errors. > > Under 10.04 I compiled 4.5.3 and 4.6.0 without any problems and both versions work as expected. > > After update to ubuntu 11.04 I got always errors while linking with these compilers: > krud@mauersegler:~/test/c++/compile_ubuntu_11.04$ /opt/_linux-gnu_4.5.3/bin/g++ main.cpp > /opt/_linux-gnu_4.5.3/bin/../lib/gcc/i686-pc-linux-gnu/4.5.3/../../../../i686-pc-linux-gnu/bin/ld: cannot find -lm > /opt/_linux-gnu_4.5.3/bin/../lib/gcc/i686-pc-linux-gnu/4.5.3/../../../../i686-pc-linux-gnu/bin/ld: cannot find -lc > collect2: ld returned 1 exit status Those compilers were configured and built for your 10.04 system so they don't know the correct paths for your 11.04 system > Also a new compilation from gcc sources on ubuntu 11.04 fails with the same problem: cannot find lc and other libs You might be able to make the old compilers work by providing the correct library paths, but if not you could install the Ubuntu gcc package then use that to rebuild gcc 4.5 and 4.6