When I typeset this code:

\documentclass{article}
\usepackage{fontspec}

\begin{document}

\sffamily
Hello world !

\sffamily
{\bfseries Hello world !}
\end{document}


the output is different if I use XeLaTeX or LuaLaTeX. I think the correct output is the first but I don't know what happens with LuaLaTeX. Any help? Thanks in advanced.

After Mico's comment:

The first is Xelatex output and the second is lualatex output.

This is the xualatex.log https://www.dropbox.com/s/yarim34cx4thksp/xelatex.log?dl=0

and this is the lualatex.log https://www.dropbox.com/s/c5n3t62vq6pb2jy/lualatex.log?dl=0

• For the benefit of the folks who don't have access to MyriadPro-BoldSemiCn on their systems, please (a) post a screenshot of the output produced by LuaLaTeX and XeLaTeX, respectively and (b) be a bit more explicit about what the issue may be. – Mico Feb 15 at 19:25
• @jpayansomet This seems to be a problem about luaotfload's detection of the bold font which might be caused by some recent changes. Is luaotfload up-to-date? – Marcel Krüger Feb 15 at 20:03
• Yes, luaotfload is up to date. – jpayansomet Feb 15 at 20:05
• @jpayansomet Could you upload the fontname database (located at /Users/javierpayansomet/Librar y/texlive/2018/texmf-var/luatex-cache/generic/names/luaotfload-names.lua.gz)? This file contains information about all installed fonts, if you are not comfortable making it publicly available you also could send it by E-Mail. – Marcel Krüger Feb 15 at 20:10
• @jpayansomet Thanks. This is a luaotfload bug, we will probably fix it with the next release. Until then, you can probably apply the answers from tex.stackexchange.com/questions/315452/… – Marcel Krüger Feb 15 at 20:40