Kile's log parser appears to be vulnerable to the same bug as TeXStudio's. The issue is diagnosed on TeX SE at http://tex.stackexchange.com/questions/358990/all-warnings-and-errors-of-my-document-refer-to-forest-sty/359152#359152. Like TeXStudio, if the log contains an empty parentheses pair (i.e. '()'), of the kind routinely output by xparse, all errors, warnings etc. will be attributed to the package, class or file responsible.

For example, in the example posted initially on TeX SE, everything is attributed to Forest. In the minimised version in the answer, everything is attributed to the minimal package.

The following code can be used to demonstrate the bug.

\begin{filecontents}{demobug.sty}
  \ProvidesPackage{demobug}
  \typeout{()}
\end{filecontents}
\documentclass{article}
\usepackage{demobug}
%\typeout{)}
\begin{document}
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

\sewt
\end{document}

The log parser attributes both the overfull box and the undefined control sequence to demobug.sty, opening that package in the editor for inspection.

Uncommenting the following line

%\typeout{)}

is a workaround which enables at least some messages to be correctly attributed. (I have tested only minimally, so I don't know how robust the workaround is.)

TeXStudio has identified the bug in their parser and will include a fix in 2.12.4 (http://tex.stackexchange.com/a/359098/). 

I don't know if the bug in Kile's parser is the same, but hope that it can be fixed also.