`tlmgr` Treating Commas in Path as Semicolons

[Karl Berry]

Hi Victor,

    tlmgr commands seem to interpret commas 

Thanks for the report. Unfortunately, as far as I can tell, we cannot
feasibly support commas (among other characters, such as braces,
semicolons, dollar signs) in the installation directory name. Sorry.
I plan to change the installer to warn about this.

Details: it's not tlmgr per se, but rather kpathsea. It's
because the basic definition of the list of texmf trees to search, the
variable TEXMF, uses brace expansion, as in (just an example):
  TEXMF = {...,$SELFAUTOPARENT/texmf-dist,...}

Where $SELFAUTOPARENT is based on the location of the binaries.
In your case, that means: C:/Users/.../User, Standard...

So when that gets expanded, the comma in your installation directory
looks like it is separating path elements.  I see no good way to discern
that the comma is intended to be part of the dir name.  It all looks the
same to the expansion code. I can imagine some heuristics, but I fear
they would end up causing more problems than solutions. In any case, it
would be a lot of work to even make the attempt, so I don't much want to
try. Sorry.

Maybe someone else will have an idea (or a patch). --best, karl.