This is a very bizarre question, so I'll explain the aetiology.
I'm a longtime \LaTeX and
knitr user, which is trying to augment his repertoire by converting to Rmarkdown.
This R package allows the creation of "reproducible reports", including the actual code used in a paper with the results and the discussion. It does so by evaluating code (mostly R and Python, but other languages are available) and formatting the output in the same markup language as the one used in the text. The resulting document is then compiled in the output form (PDF paper, but also HTML code for Web publication, slides, E-book or even Word (yuck !) or Powerpoint (yucker !) documents).
It turns out that Rmarkdown uses \LaTeX for a lot of its output, and that PDF output is in fact obtained via generation and compilation of a \LaTeX document. And that's where things are getting interesting.
Rmarkdown depends on a wrapping of tinytex, which wraps a "lightweight" user-mode installation of TeXlive, this avoiding the user the management of a \TeX installation. Currently, this dependency does not seem to be mandatory : I have installed
tinytex(the R package), but did not proceed to install the TeXlive packages ; Rmarkdown is still functional (with problems, but this is not my current issue).
However, for some options, Rmarkdown isn't able to locate some resource and queries
tinytexwhich never having installe "real" TeXlive", has an empty uset-tree, and is therefore unable to answer.
So the question is : is it possible to create a tlmgr reflecting the state of a systemwide instalatin of TeXlive done via \LaTeX packages ?