# GCC: library is linked but reference is undefined
`Linker command line is order-dependant. Only the symbols had used in the left side of the library will be defined.`
`See`
`"man GCC"`
`for more information`
## Example:
### Error
```SHELL
g++ $(shell wx-config --libs) -lwx_gtk3u_richtext-3.1 -lwx_baseu_xml-3.1 ...
```
### Correct
```SHELL
g++ -lwx_gtk3u_richtext-3.1 -lwx_baseu_xml-3.1 $(shell wx-config --libs) ...
```
###### tags: `gcc` `g++` `linker`