biblatex issues the following warning when used with the linguex package.
Package biblatex Warning: Patching footnotes failed.
(biblatex) Footnote detection will not work.
This is because the linguex redefines \footnotetext in order to support numbered examples in footnotes and endnotes.
However, redefining \footnotetext makes it impossible (difficult?) for biblatex to patch footnotes in order to support ibid and ibidem citations.
According to an answer (here), this is a warning we can safely ignore as long as we're not using an ibid citation style.
But what if a user wants to use both linguex and some ibid citation style? Is there a way to make biblatex override whatever has been done to \footnotetext?
MWE:
\documentclass{article}
\usepackage{linguex}
\usepackage
[
backend = biber,
style = authoryear-ibid,
]
{biblatex}
\begin{document}
\end{document}

linguexthus:\let\svfootnotetext\footnotetext\usepackage{linguex}\let\footnotetext\svfootnotetext. This will restore the definition of\footnotetextto that which preexisted the loading oflinguex. – Steven B. Segletes Sep 02 '16 at 16:06\letworks with a pointer to\footnotetext, whereas those packages redefine whatever that pointer points to. – n.r. Sep 02 '16 at 16:10\letdoes not work with a pointer, but makes an actual copy. Now the problem may be that what gets changed is not\footnotetext, but subsidiary routine(s). In that case, this procedure needs to be applied to the actual routine(s) that are changed bylinguex. – Steven B. Segletes Sep 02 '16 at 16:10linguexredefines\@footnotetext. So, the following should go after loading it:\makeatletter \let\@footnotetext\predefinedfootnotetext \makeatother– n.r. Sep 02 '16 at 16:22biblatexfinds out another way to patch footnotes, we need to choose between ibid footnotes or footnotes with numbered examples. I choose ibid footnotes. – n.r. Sep 02 '16 at 16:52\footnote{... \cite{} ...}; if you only use\footciteyou should be fine. You should also be fine if you only ever cite in footnotes. – moewe Sep 02 '16 at 16:59