The following MWE produces a little indentation before the label (a) of the items in the list.
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{enumitem}
\begin{document}
\noindent A line.
\begin{enumerate}[label=(\alph*),leftmargin=*]
\item A line.
\end{enumerate}
\noindent A line.
\begin{enumerate}[label=(\arabic*),leftmargin=*]
\item A line.
\end{enumerate}
\end{document}
(As you see, this does not happen using numbers.) How do I remove it?
