[tex-live] Where is the master control switch?

[Thomas Esser]

> When I try to run an ill-configured tex I get:
> 
> kpathsea: Running mktexfmt tex.fmt
> /usr/bin/mktexfmt: line 331: /texconfig/tcfmgr: No such file or directory

In that ill-configured installation,
  kpsewhich --var-value=TEXMFMAIN
expands to the empty string.

In a better installation, a texmf.cnf file defines this variable to
something that makes sense. There is a search path TEXMFCNF which defines
where to look for texmf.cnf files. I guess that your installation does
not even find a texmf.cnf file. To check, just
  kpsewhich texmf.cnf

> Is it normal to have a /texconfig directory at root level?  Or are 

It is $TEXMFMAIN/texconfig/tcfmgr.

> need to do.  Where do I go for the documentation of its contents?

If you don't go the regular route, be prepared to read some documentation
(e.g. the kpathsea manual) and to debug some scripts.

Thomas