Right now, \unravel{\tex_input:D {.tex}} fails in all engines nowadays because unravel mistakenly searches for the file {.tex}. In fact all engines seem to search for a general text before falling back to the old syntax. Needs to be tested with \openin, \openout too.
Right now,
\unravel{\tex_input:D {.tex}}fails in all engines nowadays because unravel mistakenly searches for the file{.tex}. In fact all engines seem to search for a general text before falling back to the old syntax. Needs to be tested with\openin,\openouttoo.