I am new to UOS and also not a Linux expert.
I have just downloaded the uos package and tried to compile the simplerecorder example.
On Windows, all went well and the code nicely works.
Next, I have tried the same on Ubuntu 14.04. There the compiler throws code errors, e.g. in unit uos_httpgetthread, line 75:
Error messages:
Note: DWARF debug information cannot be used with smart linking on this target, switching to static linking
uos_httpgetthread.pas(75,117) Error: Wrong number of parameters specified for call to "GetHeader"
uos_httpgetthread.pas(91,10) Error: identifier idents no member "OnHeaders"
uos_httpgetthread.pas(138) Fatal: There were 2 errors compiling module, stopping
Looks like I solved the compile problem. I still had Lazarus 1.0.9 on my Ubuntu 14.04.
On my Ubuntu 19.10 I have Lazarus 2.0.2 and there is no compile problem.