# Undefined boost library symbol (boost::system::error_category) using Qt 5.0.2 and VS 2012

• I am building a application in Qt 5.0.2 (using VS2012) which uses the boost library. The linker detects the following undefined symbol in the boost library:

"class boost::system::error_category const & __cdecl boost::system::generic_category(void)".

I found that others had encountered this error with the advice to include the boost system library which I did. This didn't fix the problem so, as a brute force experiment, I included virtually every boost library (see below) yet the problem persists. If anyone can help I would appreciate it.

Wes

• I had allso troubles with Boost by using 1.51.
I switched to 1.47 then it worked.

• Figured it out. I rebuilt the boost libraries as follows and it worked: