asmwe.textopdflatexorlatexleads to \indexentry{Text}{{\fontencoding {OT1}\selectfont I}} in the filemwe.idx. As a consequence,makeindex mweorxindex mweproduce an empty filemwe.ind. Moreover, if you usexindex mwe, the programxindexfails with the output...re/texlive/texmf-dist/tex/lu...