I did some digging around the Internet(s), and it seems like the "undefined symbol: sqrt" error (seen at run-time) is the result of a missing command-line option - that should have been used during the most recent compile.
From that I've been able to gather, this issue is seen quite often - when people are trying to compile their own copies of Apache or other open-source software. Apparently, the missing command-line option is "-ml", which instructs the compiler to link to the required math library (which contains the "sqrt" function, among other things).
I have a Linux machine up, but have no experience with compiling anything on it under GCC, etc. - much less Valve-related stuff. Not sure if I even have all the right components installed to do a successful compile (for example, do I need the Valve SDK installed on the Linux box?).
Here's a couple of examples citing the missing "-ml" option:
Why is it alway said that "fabs" and "sqrt" are undefined symbol?
math.h not working? o.0
From what I gather, no source-code changes should be required, just a re-compile (and/or possibly an updated "make" file that controls the compile).
If anybody can re-compile this bot (with the required command-line option), or show me how to do it, it would be greatly appreciated!