I recently tried downloading a pretty popular open source project [its got 10+ tags of different kinds on SO] which in turn depends on another open source project.

The 2 projects built fine, but when it came to linking these 2 with my final executable there are like loads of missing symbols. No mention of which version of project 1 is compatible with project 2 etc.

What's been your's most difficult open source experience?

Mind you, I am all for open source but documentation and examples seem to be a key missing area.