I would like to resume the post on the \usepackage{showlabels} for a moment
working on some things, I found this code very handy, but I saw that when I activate the \usepackage{showlabels}, from these problems. what could it be?
\documentclass[a4paper,10pt]{article}
\usepackage{amsmath}
\usepackage{empheq}
\usepackage{showlabels} %%<------
\begin{document}
We refer to the subequation \eqref{eq079.1} end \eqref{eq079.2} and the whole equation (\ref{eq:all}).
\begin{subequations}
\label{eq:all}
\begin{empheq}[left={\empheqlbrace\,}]{align}
&\rho = \rho+\quad \text{con}\quad \tilde{\rho}\ll\rho_{0} \label{eq079.1}
\\ \nonumber \\
&p = p_{0} + \tilde{p} \quad \text{con}\quad p_{_{0}} = \cdots\quad \text{e}\quad \tilde{p}\ll p_{0}\label{eq079.2}
\end{empheq}
\end{subequations}
\end{document}


showlabelsandempheqhas changed since 2014. This answer, which worked back then, now suffers from the same problem. – Circumscribe Nov 20 '18 at 18:38showlabelsfor enhancing compatibility withamsmathresults in the label printed twice, one without the shift due to\empheqlbrace\,and one with. Indeed, if you remove theleft=option, you'll not see the issue, because the double labels overprint each other. I can't see a workaround, sorry. Bothshowlabelsandempheqhook in\maketag@@@and conflict arises. – egreg Nov 20 '18 at 21:31\maketag@@@trying not to get my (and showlabels') heels bitten. I've opened an issue noting this, and I'll address that when I can. The incompatibility does appear to have been a change betweenshowlabelsv1.7 and v1.8, so a bit of bisection should help me narrow it down further. Thanks for finding this. – Norman Gray Dec 09 '18 at 19:34