Thanks to Jürgen, who mentions the following:
luaotfload does not find "DavidCLM". In fact, at least on my system,
there is no such font, only "DavidCLM Medium" (and other shapes). This
one is found. Apparently, luaotfload cannot infer from the one to the
other.
As opposed to LuaTEX, XeTeX also queries TEXMF so maybe it just finds
its font there.
export/export/latex/languages/supported-languages_(dvi3|pdf5)_texF
export/export/latex/languages/supported-languages_babel_(dvi3|pdf5)_texF
export/templates/Articles/Hebrew_Article_%28KOMA-Script%29_(dvi3|pdf5)_texF
+#
+# DavidCLM is not found. Comments from Jürgen:
+# luaotfload does not find "DavidCLM". In fact, at least on my system,
+# there is no such font, only "DavidCLM Medium" (and other shapes). This
+# one is found. Apparently, luaotfload cannot infer from the one to the
+# other.
+# As opposed to LuaTEX, XeTeX also queries TEXMF so maybe it just finds
+# its font there.
+# See ML thread:
+# https://www.mail-archive.com/search?l=mid&q=60ee3809d30056c191d4b2e8c57a7eda60b3e382.camel%40lyx.org
+export/templates/Articles/Hebrew_Article_%28KOMA-Script%29_(dvi3|pdf5)_systemF
+
# Ukrainian
# See comment in unreliableTests